(BEGIN VIDEOTAPE)

ANNOUNCER: Starting right now on ABC THIS WEEK. Trump, in it to win it.

DONALD TRUMP, REAL ESTATE DEVELOPER: Beautiful.

ANNOUNCER: The Donald solidifies his takeover of 2016. The massive rally, the surging poll numbers. This morning, the new sign Trump could be the leader for the long haul. He's here live

Plus, how Trump's opponents are fighting back. We'll ask Scott Walker. Can he out-trump Trump?

Biden running? His secret meeting this weekend. Does it mean he's about to jump in?

Plus, Hillary in trouble? The email firestorm growing. Why she's interrupting her vacation to get back on the trail.

And, American heroes. Breaking details about that fearless train tack down. U.S. servicemen risking their lives to stop a possible terrorist on the attack.

From ABC News, THIS WEEK with George Stephanopoulos begins now.

(END VIDEOTAPE)

GEORGE STEPHANOPOULOS, ABC HOST: Good morning. What some call a summer fling still going strong. Donald Trump drawing record crowds. He's going to join us live in a moment. But we begin with that brewing intrigue on the democratic side. Vice President Biden calling popular star Elizabeth Warren to Washington for a secret meeting on Saturday.

ABC's Jon Karl tracking all the latest from the White House. And Jon, this is the strongest sign yet that Biden is taking a serious look at this race.

JON KARL, ABC NEWS CORRESPONDENT: It sure is, George. This is a meeting between the two Democrats who could potentially pose the greatest threat to Hillary Clinton if either one of them decided to run.

Now Warren, of course, has emphatically ruled out running. Biden is seriously considering it. It's hard to imagine anything that would give him a bigger initial boost among base Democratic voters than support from Warren.

Warren, by the way, has been decided cool about Hillary Clinton's campaign. Just listen to this clip from a recent interview with WBZ in Boston.

(BEGIN VIDEO CLIP)

UNIDENTIFIED MALE: Was it a mistake for your party to anoint her as the nominee so early on?

SEN. ELIZABETH WARREN, (D) MASSACHUSETTS: Oh, I don't think anybody has been anointed.

(END VIDEO CLIP)

STEPHANOPOULO0S: So, Biden clearly sees an opening here with that lukewarm comment.

KARL: Absolutely. And especially in recent polls on the question of honesty and trustworthiness. Hillary Clinton is suffering largely as a result of this email controversy. Look at this recent Quinnipiac poll nationally, only 37 percent say that they trust Hillary Clinton, 57 percent say now.

When you look at Biden's numbers, they're almost exactly the reverse. A strong majority say that they find Biden honest and trustworthy.

STEPHANOPOULOS: The question is would he be willing to make that case if he did run.

What are they saying about timing, his advisers? I talked to one supporter this week who said it looks like Biden thinking he's about 60/40 to run. And they're feeling some pressure to make an announcement soon.

KARL: Yeah, no, what Biden himself is telling people, I am told, is that he has got quite a bit of time. He says the real deadline is that first Democratic debate, which is October 13.

But one very close Biden adviser told me yesterday that he that Biden has to do much quicker, has to make the decision much quicker. He starts, of course, way behind. He has no national organization, no fundraising. If he's going to run, he's got to get moving.

STEPHANOPOULOS: OK, Jon Karl, thanks very much.

Now the Republicans and Donald Trump dominating another week. There he is in Alabama late Friday drawing the biggest crowd of this campaign. He is standing by live after Tom Llamos reports on how his rivals are scrambling to counter the energy Trump has unleashed.

(BEGIN VIDEOTAPE)

TOMMY LLAMOS, ABC NEWS CORRESPONDENT: If there was any doubt about whether Donald Trump was dominating the 2016 race, take a look at this rock star reception Friday night, a stadium sized crowd, officials saying 30,000 on hand with the GOP front runner.

TRUMP: We need to have our borders. We need to make great deals.

LLAMOS: This rally in Alabama, a strategic choice for the Trump campaign in an early primary state. A new poll shows him now beating Jeb Bush in Florida. And the billionaire's new immigration plan the focus of the campaign.

TRUMP: You look at your gov -- you look at Baltimore, you look at Ferguson, you look at lot of these places, a lot of these gangs -- and the most vicious -- are illegals. They're out of here. First day, I will send them people -- we. Those guys are out of here.

LLAMOS: The question this morning, how does the rest of the field react? Some, like Jeb Bush, unleashing tough shots at Trump.

JEB BUSH (R), PRESIDENTIAL CANDIDATE: There's a big difference between Donald Trump and me. I'm a proven conservative with a record. He isn't.

LLAMOS: Bush's super PAC trying to highlight some of Trump's previous left-leaning views. Lying this banner over Trump's rally saying Trump for higher taxes, Jeb for Prez.

Carly Fiorina joining in as well.

CARLY FIORINA (R), PRESIDENTIAL CANDIDATE: Well, I'm not sure Donald Trump is a Republican.

LLAMOS: The alternative, to stay positive.

Put Dr. Ben Carson in that camp.

DR. BEN CARSON (R), PRESIDENTIAL CANDIDATE: I like people who are willing to say what they believe.

LLAMOS: Then there's Scott Walker. On Trump's plan to end birthright citizenship for undocumented immigrants, he first agreed.

GOV. SCOTT WALKER (R-WI), PRESIDENTIAL CANDIDATE: Yeah, absolutely. Going forward...

UNIDENTIFIED FEMALE: You should end birthright citizenship?

WALKER: Yeah, to me it's about enforcing the laws in the...

LLAMOS: Then backed off.

WALKER: I'm not taking a position on it one way or the other.

LLAMOS: The Trump juggernaut still leaving top tier candidates on unsure footing.

For this week Tom Llamos, ABC News, New York.

(END VIDEOTAPE)

STEPHANOPOULOS: Thanks to Tom Llamos for that.

Now let's talk to the man himself. Donald Trump joins us by phone. A lot to talk about this week, Mr. Trump.

But I want to begin with that news about Joe Biden, some talk that he may be seriously considering the race right now, meeting with Elizabeth Warren. Might be getting in. Would he be a tougher opponent than Hillary?

TRUMP: I don't think so. I think they're the same. I think that Hillary may be very damaged, however, George because of the email thing. You look at General Petraeus, what's happened to him, how he's been destroyed and what he did was a fraction of what she's done.

But I don't know. Assuming she could get over that, which I just don't know how she possibly can, but assuming she could I would say it would be pretty equal.

STEPHANOPOULOS: OK. But, let's talk about you right now and your new immigration plan. You've been talking about on the stump, all of opponents having to react to it at this point. Jeb Bush one of the people that reacted to this thing, it's going to cost hundreds of billions.

And look at this from the American Action Forum, conservative group. They say the federal government would have to spend roughly $400 to $600 billion to address the 11.2 million undocumented immigrants. Each immigrant would have to be apprehended, detained, legally processed, transported to his or her own country. In turn, this would shrink the labor force by 11 million workers, reduce real GDP by $1.6 trillion.

Are you willing to pay that price? And where are you going to get the money?

TRUMP: Well, first of all they're wrong. And, you know, Jeb is a very low energy person. He'd never be able to do it. He's the one that said they come out of an act of love, OK. This is an act of love. These are people coming and many of them -- you look at what's happening with the crime. Many of them are really causing tremendous problems. And they would be out really fast, immediately. First day we start that movement.

We need a wall. We have to get a wall. We need great security. And we're going to have a wall that will be not let people in, George.

And, by the way, legally, if you're legal you can come in. And we'll cherish you for coming in.

STEPHANOPOULOS: But let me press you on the costs right there, Mr. Trump. They're saying $400 billion to $600 billion. It would require big government apparatus to take everybody down. If you don't think those numbers are right, how much is it going to cost and where are you going to get the money?

TRUMP: Well, it's costing us $130 billion a year and that's peanuts compared to what the real cost is, George, for the way we have it now. You have so many illegals. We don't even know how many illegals. I hear 11 million. I hear 30 million.

The government has no idea. We have lost control of our country. We've lost control of our borders. The government has no idea how many illegals there. I've been hearing 11 million for five years. Then the other day I heard 30.

Nobody has any idea (INAUDIBLE)...

STEPHANOPOULOS: So if there's no idea, how are you going to round them all up?

Where are you going to get the money, where are you going to get the forces?

Exactly how are you going to do it?

What are the specifics here?

TRUMP: George, it's called management. And the first thing we have to do is secure the border. But it's called management. And we'll get people back in, the really good ones, we're going to expedite it, so they get back in, so they can at least come in legally.

But we have to do it...

STEPHANOPOULOS: You keep declaring how you're going to do it...

TRUMP: It's management.

STEPHANOPOULOS: -- but you don't say...

TRUMP: We don't...

STEPHANOPOULOS: -- how.

TRUMP: Excuse me, George?

STEPHANOPOULOS: You declare how you're going to do it, but you don't say how.

TRUMP: George, I'm telling you, it's called management. You can do this and we can expedite the good ones to come back in. And everybody wants that. But they have to come in legally.

We have a country, we have to have -- we're a country of laws. We're a country of borders.

How can you have a country without a border?

How can you have a country without laws?

We have to do it. And by the way, what you said in your piece initially is the gang members. You look at the gang members in Baltimore, Chicago, in Ferguson, these people, a lot of them, are illegals. These are rough dudes. And we're going to get them to hell out fast.

STEPHANOPOULOS: I -- I understand that you think it's a huge problem, but I still don't hear specifics on how you're going to do this.

Are you example...

TRUMP: Well, you'll see...

STEPHANOPOULOS: -- for example...

TRUMP: -- my specifics, George. But my specifics are very sample -- I'm going to get great people that know what they're doing, not a bunch of political hacks that have no idea what they're doing, appointed by President Obama, that doesn't have a clue. I mean that man doesn't have a clue.

People are walking across the border right now, right in front of these great people that we have. We have wonderful Border Patrol people. They can do their job. but they're not allowed to do the job.

People are walking right into our country totally un -- nobody even knows where they come from. They walk right past guards that are told not to do anything.

STEPHANOPOULOS: Do you expect neighbors to start turning in neighbors?

TRUMP: I don't know what's going to happen. I can tell you this, we have to have a country -- we're a country of laws and we have to do it that way, George. There's nothing we can do about it if we're going to -- if we're going to stand as a country.

There's no choice. We have no choice. We have to do it properly.

Now, the candidates that are running against me like -- like Jeb Bush, he has no clue. He's never going to be able to do anything. You just looked at what's happened with him over the years and what's happened with -- the last thing we need is another Bush.

But Scott Walker has changed his mind now, because he keeps going back to his pollster, and his pollster says, oh, Trump has a good idea, oh, Trump has a bad idea, oh, no, wait a minute, Trump has a good idea.

These people don't know what they're doing, George. They're politicians.

STEPHANOPOULOS: I (INAUDIBLE)...

TRUMP: They don't know management. I get the best people and we will do it properly and we will do it humanely and get the good ones back in.

STEPHANOPOULOS: I still haven't heard the specifics on how you're going to do that, but I'm going to move on...

TRUMP: Well, you'll hear it, George. Don't worry about it.

STEPHANOPOULOS: I'm going to move on right now.

TRUMP: You'll hear it.

STEPHANOPOULOS: Scott Walker...

TRUMP: It's called good management and it's called great people.

STEPHANOPOULOS: You know, you talked about Jeb Bush just a minute ago. You said he's a low energy guy. I want to talk about an -- an article that turned out in "New York" magazine, Gabriel Sherman talked to a friend of yours, who says he is an informal adviser. He says you called him and warned that friend, if I'm going down, then Bush is going down with me. He's not going to be president of the United States.

Did you say to -- that and is that what you're going to do?

TRUMP: No, that's totally false. I don't know where this comes from. I'm just hearing it for the first time. I don't mind Jeb Bush. I think he's a nice person. I just don't think he has the energy -- you need energy for this job. You need -- you can't be soft. And we need -- we're a country that's in trouble. We owe $18 trillion. It's going to be up to $20 trillion in a very short period of time, which is a very, very border number, when you hit over $20 trillion.

And we need a person with a lot of smarts, a lot of cunning and a lot of energy. And Jeb doesn't have that. I think he's a very nice person. If he came president -- if he became president, good luck. It's another Bush. It's going to be the same old story.

STEPHANOPOULOS: Let me ask you...

TRUMP: But I have nothing against Jeb Bush. I think he's a very nice person.

STEPHANOPOULOS: Let me ask you a more philosophical question.

Which failure in your career taught you the most?

What did you learn from it?

TRUMP: I've had very few failures, George. And if I do have a failure, I try and make it a success. for instance, if a market collapses in the midst of a big construction job, which I've had happen a number of times, in some cases, I've made those jobs more successful.

I go back to the banks. I fight with them. I negotiate. I do all sorts of things. And I've had deals that should have been disasters and would have been for most people and they've become great successes, actually more successful than if the market had stayed good.

But I would say this more than anything else, you have to learn from tough times. And I've learned a lot.

STEPHANOPOULOS: You talked about Scott Walker just a minute ago. And he drew a lot of headlines this week talking about his efforts to try and maybe out-Trump you, one from "The New York Times," (INAUDIBLE) stepping away in Iowa, Walker adopts a Trump-like stance.

"The Washington Post," "fading in the polls, Walker aims to attract Trump supporters."

Reuters, "in a bid to jump-start his campaign, Walker tries to channel Trump."

"National Journal," "how Scott Walker plans to win back Donald Trump's supporters."

Are you worried?

TRUMP: Well, I'm not worried because his state is really in trouble. I mean it's a fantastic place. It -- I love the people of Wisconsin, but if you look at what's going on, they have a $2.2 billion deficit. They were supposed to have a surplus of $1 billion and they have $2.2 billion. There's tremendous divisions throughout the state.

The roads are being built properly. The -- you know, he stopped a lot of work because he doesn't want to raise taxes. So instead of raising taxes, he's borrowing to the hilt and the state is very overleveraged. And it's number 38 out of the states. It's number -- it's ranked number 38. That's no good.

So, you know, I -- I'm honored that he wants to copy me and he's a nice man. He was up -- I -- I gave him campaign contributions when he was running for governor. I like him very much.

But his state has not performed well. we need somebody that's going to make it perform well, this country perform well. And I'm the -- I'm the one to do it. I will do a great job. And people are seeing that and it's being reflected in the polls.

I mean Reuters just came out with a brand new poll yesterday, 32 percent for Trump. I mean people want to see real change, not Obama change. He used the word change. His change was a bad change. They want to see proper change. They want to see great change. They want to see our country be great again, George.

STEPHANOPOULOS: Donald Trump, thanks for your time this morning.

TRUMP: Thank you very much.

STEPHANOPOULOS: OK, let's give Scott Walker a chance to respond right now.

He joins us this morning from Alabama.

Governor, thank you for joining us this morning.

You just heard Donald Trump say Wisconsin is not performing.

Your response?

GOV. SCOTT WALKER (R-WI), PRESIDENTIAL CANDIDATE: Well, he's using the talking points of the Democrats. Those talking points haven't worked in the past four and a half years, as we won three elections in four years, not just with Republican support, but with a huge margin amongst Independents and even some discerning Democrats.

Why?

Because we took a $3.6 billion budget deficit. We fixed it. We did it while cutting taxes by billions of dollars.

Our roads are actually -- are better. Our schools are better. Our state is better.

Those are the same talking points the Democrats used. They didn't work in the past. They're not going to work now.

But the one thing that I do want to clarify is I do think that there is some real frustration out there. It's way you not only see his numbers up, you see some of the other candidates who have not run for office before. They're angry at Washington. Heck, I'm angry at Washington. I'm angry at my own -- my own party leadership, who told us they were going to repeal Obamacare and we still don't see a bill on the desk of the president.

I think that's where the real frustration is.

In the end, if people want someone who's going to fight, but not just fight, fight and win and actually get results and do it without compromising common sense conservative principles, I'm the candidate.

STEPHANOPOULOS: It sounds like you're following through on what "The Washington Post" reported this week. They reported on a conference call you had with your fundraisers, where you said you had to do better in protest, passion and policy. Is that right?

WALKER: Yes, I think there’s no doubt it. I think people want to see what they saw the other day at the Iowa State Fair. We had protesters who wanted to try to come up on the stage and I said I’m not intimidated by you, sir. I’m not intimidated by the left. I’m not intimidated by the special interests from Washington. I’m certainly intimidated by the big government union bosses.

But earlier on there were a few even in my own party. You know, our state assembly was great, most of our state senate, but a few of our state senators, some of whom had been in leadership, did not want to do the big, bold reforms we did and we took them on just like I’ll take anybody on, including the leadership of my own party in Washington, if that’s what it takes to do what’s right for the American people.

STEPHANOPOULOS: Also been taking on this question of birthright citizenship and the Fourteenth Amendment. Let me just put the first sentence of the Fourteenth Amendment up there on the screen right now. “All persons born or naturalized in the United States and subject to the jurisdiction thereof are citizens of the United States and of the state wherein they reside.”

Do you support the first line of the Fourteenth Amendment?

WALKER: Well, George, let me step back for a second and tell you an interesting story. Last month, I was in a small town in Iowa called (INAUDIBLE). In fact, I lived there as a kid for a while. And a family came from Waukesha, Wisconsin, to confront me. They -- the father in particular was upset that I was one of the 25 governors that went to court and stopped the president. And I told that father in a very tense situation with the media all around, including some from ABC News and others out there, I told that father I felt bad for him and his family, I really do, I feel bad for families like that. But I told them that this president had said I believe some 22 times, 22 times, before he did what he did last November, that he couldn’t he do it. He said that he was the president, not the emperor, that he wasn’t above the law, and then he went out and changed the law by his actions. It took me and 25 -- or excuse me, 24 -- governors to stop him in court.

The problem here, we need to address the root problem of the issue, which is we need a president who’s going to secure the borders, not just give lip service to it like we’ve seen over the past couple decades -- secure the border and enforce the laws. My point all week has been and continues to be, as it was last month, until we address those core problems, we’re going to -- we’re not addressing the real issue and Americans are right to be upset with that.

STEPHANOPOULOS: I understand that’s what you feel we have to address, but this is simply a yes or no question. Do you support that line of the Fourteenth Amendment?

WALKER: Well, I said the law is there. And we need to enforce the laws including those that are in the Constitution. My point is having this debate about anything else when we don’t have politicians who are committed to actually securing the border and enforcing the laws, which means very simply in our country e-verify. Making sure that every employer ensure that the people working for them are legal to work in this state -- in this country. That will resolve the problems you’re talking about and that’s what I’ve been talking about this week.

STEPHANOPOULOS: So you’re not seeking to repeal or alter the Fourteenth Amendment.

WALKER: No. My point is any discussion that goes beyond securing the border and enforcing the laws are things that should be a red flag to voters out there, who for years have heard lip service from politicians and are understandably angry because those politicians haven’t been committed to following through on those promises.

I hope the one thing people see, in my state, I had 100,000 protesters on a different issue. I had all sorts of death threats and all sorts of other views. I think people in my state will tell you whether they agree or disagree with me on the issue, the one thing I do is when I make a promise I follow through on it. My promise is to truly secure the border and enforce the laws of this great country.

STEPHANOPOULOS: Let’s talk about health care. You put out a plan this week calling for the replacement of Obamacare with a series of tax credits for everyone that would be escalating over age. This is what one of your rivals, Governor Bobby Jindal, had to say about that.

(BEGIN VIDEO CLIP)

GOV. BOBBY JINDAL (R-LA), PRESIDENTIAL CANDIDATE: Scott Walker’s plan actually does create a new entitlement program. It actually does guarantee universal coverage through government subsidies for every American. One estimate this week says it would cost over $1 trillion, and he doesn’t tell us how he would pay for this plan.

(END VIDEO CLIP)

STEPHANOPOULOS: So how much will your plan cost? How are you going to pay for it?

WALKER: Well, he’s just wrong on that, and in fact conservative commentator after commentator from “The Wall Street Journal” to “The National Review” and plenty of others out there have said this is the best plan out there. In fact, it’s one of the only plans out there. They said it’s the best plan, it’s about freedom, it’s about giving patients and their families the freedom to control their own health care decision and to control their own money.

We repeal Obamacare immediately. On Day 1 we send a bill up to Congress, and on Day 1 we get rid of the special provisions for Congress, their families, their staff, and everyone else, to make sure they repeal it entirely, immediately. And then we give people a tax credit for those who don’t have health insurance from their employer. If you get it from your employer, it’s not going to be touched. If anything, your premiums are likely to go down because repealing Obamacare and putting in place our reforms will actually help lower health care costs, not raise them, as we saw under Obamacare.

But we give people a tax credit, it goes up by age. Because before Obamacare that’s what happened. Your health care costs go up over age, the credit goes up over age. We allow people to apply that to the health care plan they want, or not buy health care insurance if they don’t want. But we put the freedom back in the hands of the American people. And for us it’s a simple way to do it that’s cost neutral. It repeals all of the trillion dollars’ worth of tax increases that you see under Obamacare, gives us one of the biggest tax cuts we’ve had in the past 40-some years, one of the best pro-growth plans out there, and we do it by making sure we have a tax system that appropriately acknowledges some of the top tier health insurance plans and by giving Medicaid back to the states where there’s real reform. That makes it cost neutral.

STEPHANOPOULOS: Finally, heard Donald Trump say he doesn’t think he can overcome this e-mail issue. Do you agree with that? Will this still be an issue in the general election?

WALKER: Well, I think she’s got all sorts of problems when it comes to health care. Hillarycare is more about the ruling class than about the middle class. She’s trying to give special breaks, you’re talking about giving special breaks to some of her biggest supporters while the rest of us are stuck with it. And when it comes to e-mail, I don’t think Americans can trust her. Every day we see more information about these e-mails and they’re not about e-mails, they’re really about national security. She’s put my national security at risk; she’s put your national security at risk. She’s put the American people’s national security at risk. Hillary Clinton would be a pretty good deceiver-in-chief but I don’t think we can trust her to be the commander-in-chief.

STEPHANOPOULOS: Sounds like you’re all ready to make it an issue if you get the nomination. Governor Walker, thanks very much for your time this morning.

WALKER: Thank you, George. Good to be with you.

STEPHANOPOULOS: And when we come back, those three American heroes who risked their lives to stop a deadly terror attack. Fresh details on their harrowing story.

And what was behind the worst week on Wall Street in years? What’s next for the markets and your 401(k)? That analysis is next.

(COMMERCIAL BREAK)

STEPHANOPOULOS: We are back now with those American heroes who took down a terrorist in France. Unarmed, unafraid, they acted on instinct, wrestling away an assault weapon as the attacker slashed them with a knife.

Authorities say they prevented a massacre and ABC’s David Wright is in Paris with the latest details of their stunning bravery.

Good morning, David.

DAVID WRIGHT, ABC NEWS CORRESPONDENT: Good morning, George. You’re right: stunning is the word for it. These three Americans were vacationing here in France, two servicemembers and a college student, childhood friends, who were on that train bound for Paris when a gunman burst into the car and started shooting. Without thinking of their own safety, they leapt into action.

(BEGIN VIDEOTAPE)

WRIGHT (voice-over): Slightly battered by clearly in good spirits, Airman First Class Spencer Stone waved to reporters after being released from the hospital. He’s one of three Americans being hailed as heroes for thwarting what could have been a deadly terror attack on a Paris-bound train.

SPENCER STONE, U.S. AIR FORCE: Dude, I tried to shoot him but --

WRIGHT: The immediate aftermath captured on cell phone video, that’s Spencer bleeding from the neck and hand after disarming the suspect, now hog-tied on the floor, his arsenal of weapons nearby. Stone was on the train with two childhood friends, Army National Guardsman Alex Skarlatos and a college student Anthony Sadler when the gunmen emerged from the bathroom wielding an AK-47.

SPENCER STONE, U.S. AIR FORCE: We see the gunman enter the back of the train with the AK in his hand. and he's cocking it, about to shoot it. And my friend Alex just yelled Spencer go.

ALEX SKARLATOS, U.S. NATIONAL GUARD: Spencer got to the guy first, grabbed the guy by the neck and I grabbed the handgun. We were scared, for sure, but I mean adrenaline mostly just took over because I mean I didn't even have time to think.

WRIGHT: A British businessman also made the split second decision to help subdue the gunman.

CHRIS NORMAN, CONSULTANT: It was purely about survival. I said to myself, OK, maybe I have a chance if I get up and I help as well.

WRIGHT: French authorities say the suspect, identified as 25-year-old Ayoub El-Khazani was on a security watchlist, thought to have ties to radical Islamist groups.

This country is, of course, still on high alert after the deadly Charlie Hebdo attack in January. The authorities here thankful that that scene was not repeated thanks to these quick thinking Americans.

(END VIDEOTAPE)

WRIGHT: Tomorrow, the French president plans to thank them personally at a ceremony here at the Elysee Palace -- George.

STEPHANOPOULOS: And they deserve every accolade they get. Thanks, David.

Now to that huge selloff on Wall Street this week. The Dow dropping 6 percent, more than 500 points on Friday alone, its worst day in nearly four years. Investors and everyone with a 401(k) bracing for more turbulence in global markets opening later today.

Our market experts Rebecca Jarvis tracking it all. And what triggered this big fall this week?

REBECCA JARVIS, ABC NEWS CORRESPONDENT: Two key issues here, George. First off, fears of a global economic slowdown. And the federal reserve on the verge for the first time in six years of hiking interest rates, which means the cost of borrowing goes up for everyone. Anyone who wants a mortgage, a car loan, a credit card, that gets more expensive.

STEPHANOPOULOS: And what are you hearing about what is going to happen next when markets open tomorrow?

JARVIS: Well, what we're hearing right now is that things are pointing lower. But, of course, no one can call the future. No one knows with certainty. What you look at is where the selling is. And it is widespread right now. The Blue Chips, Wal-Mart, Exxon, Apple. Shares in Apple are down 20 percent since April. These are sizable companies. And they're all facing lower.

And then you look at the fear gauge on Wall Street. It's called the volatility index where they actually measure fear. That spiked to the highest level so far this year on Friday. So, we're setting up for a very volatile week.

What we're going to be watching tonight is obviously when China opens, because China has been very significant. The weakness there has been rippling over into our markets for some time now.

STEPHANOPOULOS: A lot of eyes on that. OK, Rebecca, I know you'll be watching it as well. We'll talk to you tomorrow.

And up next, here the Democrat looking for traction by taking on Trump. But is Martin O'Malley ready to get tough on Hillary, too? He joins us live.

(COMMERCIAL BREAK)

STEPHANOPOULOS: Our roundtable and Martin O'Malley standing by. And check out Washington's other big news this weekend, two new cubs born Saturday to giant panda Mei Xiang. The National Zoo's chief vet said the second cub caught them by surprise, never showing up on the ultrasound. Names are still to come. And we'll be right back.

(COMMERCIAL BREAK)

(BEGIN VIDEO CLIP)

MARTIN O'MALLEY (D), PRESIDENTIAL CANDIDATE: Our country is already great, but people like Donald Trump sell it short when they sell their workers short.

TRUMP: I know nothing about him. I think he's got less than 1 percent in the poll. And I did see my beautiful building on television. It's a beautiful -- tallest building in Las Vegas. I'm very proud of it. The most beautiful building in Las Vegas.

I know he was in front. Martin O'Malley was there to try and get some publicity, which he desperately needs.

(END VIDEO CLIP)

STEPHANOPOULOS: And Governor Martin O'Malley joins us now from Davenport, Iowa, after that appearance in from of Trump's hotel in Las Vegas this week.

Governor, thank you for joining us this morning. That was actually pretty mild from Mr. Trump.

O'MALLEY: Thank you, George.

STEPHANOPOULOS: He also said this week that you're a "disgusting little weak pathetic baby." Your response?

O'MALLEY: My response is I'm not going to get into a name-calling debate with Mr. Trump. But I do take great exception to the hateful language that he uses with regard to whole groups of new American immigrants.

And I also have a great deal of disagreement with the economic policies he espoused, which are good for billionaires, but bad for working people, including those folks working at minimum wage at his hotel that he will not even allow to have the right to be heard, and to bargain collectively for better wages.

The biggest challenge in our country right now, George, is, how do we get wages to go up again for Americans instead of down? Seventy percent of us are working harder, but not getting ahead. And that's not the way our country is supposed to work or our economy is supposed to work.

And Mr. Trump's policies are absolutely the wrong sort of policies that would perpetuate this sort of wage stagnation.

STEPHANOPOULOS: Do you think he has any chance of being the nominee?

O'MALLEY: Excuse me? Does Donald Trump? I suppose he could, which is why -- you know, why we have such an outstanding opportunity here, if only the Democratic Party would start holding debates.

I mean, when you listen to their debates, very few of their candidates take him on directly for the hate-mongering, for the hateful speech about women and about immigrants.

And so we have an opportunity as the Democratic Party, if we would start holding debates, to talk about the ideas that actually make wages go up: raising the minimum wage; allowing workers to organize; making investments in our own country again.

These are the things that will actually make the American dream real again.

STEPHANOPOULOS: I know you're calling for more debates. The first one is scheduled for October, October 13th. But I wonder what kind of case you're going to make over the course of those debates.

Your Iowa co-chair, George Appleby, actually said a little bit back that the major factor in this nomination fight is going to be age. He said, I don't think we're going to back to someone much older, whether that's Bernie Sanders, age 73, Hillary Clinton, 67.

Do you agree that's going to be a major factor? And is that a case you're going to make?

O'MALLEY: Well, I believe that the country is looking for new leadership. We can't be this dissatisfied with our economy is working for most of us, or this dissatisfied that our very divided and polarized national politics, and think that a resort to old names is going to move us forward.

So I am in Iowa today. I've now visited 30 of the 99 counties. And we're getting a very strong response on the ground from those activists who actually make the decision in the caucuses.

And the phrase I hear over and over again, George, is the phrase "getting things done." There are many fine candidates in the Democratic Party who espouse progressive goals and values, and will make progressive promises.

But I'm the only one in our party who has 15 years of executive experience actually getting these things done, actually passing a living wage, passing the Dream Act, passing marriage equality, creating an economic environment that the U.S. Chamber of Commerce called the number one state in America for innovation and entrepreneurship.

These are the things that we need to do as a country so that we can include more of our people more fully in the economic life of our nation.

STEPHANOPOULOS: So you're going to hammer home on getting things done. Will it be harder to make that case if Vice President Biden gets in?

O'MALLEY: I would -- you know, I have a great deal of respect for Vice President Biden. He's a very, very good and decent man. It would be nice to have at least one more lifelong Democrat in the race.

And I think his wisdom, I think his experience would add much to this…

STEPHANOPOULOS: Is that a shot at Bernie Sanders…

O'MALLEY: … Democratic conversation.

STEPHANOPOULOS: … for being part of the socialist party?

O'MALLEY: No. It's a compliment to Vice President Biden for also being a lifelong Democrat.

STEPHANOPOULOS: OK. One other (INAUDIBLE) about Hillary Clinton. You have said that this whole issue of emails is a distraction, a distraction from the campaign. You've refused to take it on so far.

But I want to show you some poll numbers that came up this week from the Quinnipiac poll from key states of Florida, Ohio, and Pennsylvania. They were asked, is Hillary Clinton honest and trustworthy?

Sixty percent in Ohio said no. Sixty-four percent Florida. Sixty-three percent in Pennsylvania said no. You just heard Scott Walker call it -- say Hillary Clinton would be the "deceiver-in-chief."

Do you believe she is honest and trustworthy?

O'MALLEY: This is why, George, we need to have debates, because so long as our Democratic Party is not talking about the issues that matter most around the kitchen table, the only question that will be asked every day, and it's a legitimate question, by media people like yourself, or by the Republicans, are questions about Hillary Clinton's emails.

Those are questions that I will leave to her and to her lawyers to answer. But as a party, we need to wake up and we need to have start having debates about the issues that really matter, like making college more affordable for more families, making wages go up and not down, making the investments that allow us to move to a 100 percent clean energy future as a nation so we can square our shoulders to the challenge of climate change.

Until we start having debates, and offering those ideas that move our country forward, we're going to be bogged down in questions of, what did Hillary Clinton know and when did she know it?

And we cannot allow our party to be branded by those sorts of questions of the past. We have to look to the future. And we have to offer the ideas that move our country forward for the future.

STEPHANOPOULOS: Real quick…

O'MALLEY: That's why these debates are so important.

STEPHANOPOULOS: Do you think you can convince the DNC to add more debates?

O'MALLEY: I think the DNC will become convinced and say, look, the poll numbers that you just put up there that we're really hurting ourselves by not putting forward the ideas that serve our national interest.

The new ideas and the new generation of leadership that people are looking for is going to be found in the Democratic Party, not the hate-mongers of the Republican Party. We need to offer these ideas.

STEPHANOPOULOS: Governor O'Malley, thanks for your time this morning.

O'MALLEY: Thank you, George.

STEPHANOPOULOS: "Roundtable" is up next. What do they make of Hillary's troubles, Trump's dominance, and the remarkable grace of Jimmy Carter?

(BEGIN VIDEO CLIP)

JIMMY CARTER, 39th PRESIDENT OF THE UNITED STATES: Well, I'm ready for anything. I'm looking forward to a new adventure.

(END VIDEO CLIP)

(COMMERCIAL BREAK)

(BEGIN VIDEO CLIP)

ED HENRY, FOX NEWS SENIOR WHITE HOUSE CORRESPODENT: You were in charge of it. You were the official in charge. Did you wipe the server?

HILLARY CLINTON (D), PRESIDENTIAL CANDIDATE: What, like with a cloth or something? We have turned over the server. They can do whatever they want to with the server to figure out what's there or what's not there.

But we turned over everything that was work-related, every single thing. Personal stuff, we did not. I had no obligation to do so, and did not.

Thank you all.

(END VIDEO CLIP)

STEPHANOPOULOS: Hillary Clinton right there, taking those questions on her emails this week, showing a bit of frustration, but then moving on. I want to talk about that on our "Roundtable."

We're joined by Democrat Bill Richardson, former governor of New Mexico, cabinet secretary, U.N. ambassador for President Clinton as well; Republican strategist Ana Navarro, very close to Jeb Bush; Rich Lowry, editor of "The New Republic." Editor of "Time" magazine, Nancy Gibbs. And Matt Bai, the national political columnist for Yahoo! ! News.

And let's begin with Hillary Clinton and the e-mails.

Rich Lowry, let me go to you.

The cover of "The Week" magazine says, "Is this Going to Sink Hillary's Campaign?" this week. The Hillary team says that is overblown.

What do you think?

RICH LOWRY, EDITOR, "THE NEW REPUBLIC": Well, the problem she has no one, George, believes her. The reason why she set up this private system was clearly to maintain complete control over her official records. And now she is a hostage to fortune, depending on what the FBI concludes about the lawfulness of this arrangement and depending on what of her personal emails are recovered, so-called personal, because it's really hard to believe that she sent tens of thousands of emails as secretary of State all about her yoga routines and wedding cakes and all the rest of it.

STEPHANOPOULOS: Although it's also hard to believe that they would make such a declarative statement if they thought there was anything there that had been marked classified.

But I have talked to some Clinton supporters, Nancy Gibbs, who do think that at least she's going to come out and sort of say what she has said before, when she said yes, it was probably a mistake to se this personal system up.

NANCY GIBBS, EDITOR, "TIME" MAGAZINE: I think the problem is the declarative statements haven't been that declarative. It was, you know, nothing was classified and then it was nothing was marked classified at the time. Every time the statements change, I think it reinforces the notion that -- that the whole story isn't out.

And, you know, apologizing isn't necessarily the strongest suit for her. And so I -- I don't know that you're going to go that far to say I made a mistake.

But I -- you do increasingly hear people in her party saying -- saying without some acknowledgment that this looks really bad and feels really bad in a visceral way to voters on the trust factor, it's going to be very hard for it to be behind her.

STEPHANOPOULOS: And -- and Matt Bai, there are some questions about this Quinnipiac Poll, but it's going to be an alarm bell for Democrats here.

MATT BAI, NATIONAL POLITICAL COLUMNIST, YAHOO! NEWS: Oh, yes. Oh, yes, it is an alarm bell. I mean -- I mean, look, we always hear it in politics, George, right, that it's not the crime, it's the cover-up. I think here, it's not the cover-up, it's the attitude. It's -- and this is what's driving this trust deficit is, you know, the idea that whether people care really about the emails or the servers or whether they understand the details, there is this attitude that I don't have to answer these questions, I shouldn't have to answer these questions.

She walked away from the media, you know, last week...

STEPHANOPOULOS: Yes, but she did answer...

(CROSSTALK)

STEPHANOPOULOS: -- to be fair, she did answer the questions first.

BAI: But very testily and incompletely. And as you say, with a -- with a very tepid apology.

I think that's the issue that goes forward even more than whatever happens with the email servers.

What Democrats have to be worried about when they look at those numbers on the trust deficit is that the signal is one of entitlement, that the signal is one that says I'm taking this nomination, I'm the only one out there and I'm not going to have to answer some of these questions that -- that people want answered.

I -- I think that would worry me if I were running her campaign.

STEPHANOPOULOS: And -- and, Bill Richardson, Joe Biden obviously watching this pretty closely. He has this meeting with Elizabeth Warren yesterday, clearly reaching out in all the early states, as well.

Do you think he gets in?

BILL RICHARDSON, FMR GOVERNOR OF NEW MEXICO: I don't think he gets in. I think the personal situation he's going through and the fact that Hillary Clinton is way ahead. I mean I knew that she's having these problems now, but with fundraising, with her -- she's got a superb organization, you know, and by the way, she will be very strong after Iowa and New Hampshire in -- in Super Tuesday, in minority states with a broad coalition of women and progressives and minorities.

I don't think he gets in.

But if he gets in, he will be a formidable challenger.

STEPHANOPOULOS: And I should point out, you have had your -- your difficulties with the Clintons in the past, even though you worked for President Clinton. You endorsed Barack Obama in 2008. It caused a rift with the Clintons.

But now, some mending of fences?

RICHARDSON: We patched things up with both Clintons, with Secretary Clinton and President Clinton. You know, for seven years, there was hostility when I did the endorsement of President Obama, which I stand by. But I didn't do it right. You know, I didn't handle that right. And so we patched things up. We've had long conversations with both of them. I'm supporting her now, because I think she's got the best candidacy.

Talk about the issues. I mean what she's come out with on the economy, on job growth, on climate change, on immigration, on foreign policy, she was a good secretary of State.

ANA NAVARRO, REPUBLICAN STRATEGIST: Well, I'm -- I'm glad you did that, Bill, because, you know, the Clintons have a long memory. I thought if she became president, you were going to have to self-deport, buddy.

UNIDENTIFIED MALE: And let me assure you, George, I have not patched things up with the Clintons, just in case you're (INAUDIBLE).

(LAUGHTER)

(CROSSTALK)

NAVARRO: -- you need to patch things up with James Carville, who I remember had some very choice words for you at that time.

RICHARDSON: Well, you know, I -- I'll tell you the truth. I was very close with President Clinton. So for seven years, you know, this -- this was like an albatross. So I don't want anything from them. But I wanted to clear this up.

I still think she's, by far, the best candidate of all the candidates. She's got the experience. She's got a tremendous amount of policy positions that are new that need to be looked at.

STEPHANOPOULOS: Ana, what -- what about this maneuvering by Joe Biden at this point?

No one can get inside his head, I guess, right now.

But the question I would have if he gets in is what case does he make?

Would he go directly at these issues of honesty and trustworthiness?

NAVARRO: You know, I'm not even sure that he needs to go to those issues, because the press is doing so much. I think the case he makes is I've got as much, if not more, foreign policy experience and I don't have any baggage.

The problem with this Clinton email story is that it's not going away. There's new revelations practically every week and it's been an a drip, drip, drip now for, what, six months?

And her response to it is really not the best. We see her joke about it. You know, when your email use is under DOJ investigation, you really shouldn't be laughing.

RICHARDSON: You know, this thing is overblown.

NAVARRO: And we all go -- but we all (INAUDIBLE)...

RICHARDSON: This email thing is overblown.

NAVARRO: (INAUDIBLE).

RICHARDSON: Past secretaries of State have done it at the time, 2009, this was a -- a practice you could make...

UNIDENTIFIED MALE: Well, there was...

RICHARDSON: -- a choice.

STEPHANOPOULOS: Colin Powell did it at the very beginning (INAUDIBLE)...

RICHARDSON: You know what I would have said if -- because I was in the cabinet. I would have said, you know what, I don't want an official classified email system, I want to have my own private server.

Why?

Because of WikiLeaks, because of hacking, because of leaks.

STEPHANOPOULOS: But no one else in the cabinet did.

RICHARDSON: Well, Colin Powell did.

UNIDENTIFIED MALE: Colin Powell didn't set up his own server. And you look at former CIA director, John Deutsch, had to be pardoned by Bill Clinton for keeping classified information...

RICHARDSON: But is there any...

UNIDENTIFIED MALE: On unsecure computers...

RICHARDSON: But wait...

UNIDENTIFIED MALE: -- at home.

RICHARDSON: Is there any...

(CROSSTALK)

RICHARDSON: -- classified or unclassified that -- there's no classified...

UNIDENTIFIED MALE: Anyone...

RICHARDSON: -- email. There's no -- there's no...

UNIDENTIFIED MALE: -- anyone who's served...

RICHARDSON: -- there's nothing there.

UNIDENTIFIED MALE: -- in government and handled classified material knows this is appalling and if they did this -- a similar thing, their career would be at risk and they'd be at -- in legal jeopardy.

And that's why this is so serious.

RICHARDSON: But there's no classified emails.

NAVARRO: But, Bill, you don't know that j

(CROSSTALK)

NAVARRO: -- there have been 300...

UNIDENTIFIED MALE: There is classified material on her emails.

NAVARRO: -- emails that have been identified...

RICHARDSON: Overblown.

NAVARRO: -- for further review.

RICHARDSON: This is an overblown...

NAVARRO: There's been -- you actually...

RICHARDSON: This is political. This is political.

NAVARRO: No...

(CROSSTALK)

RICHARDSON: You guys are using this.

UNIDENTIFIED MALE: The FBI is not political.

NAVARRO: Listen, they -- they -- it is not political when you're talking about the Department of Justice and the FBI. It is, you know, was it political against David Petraeus?

RICHARDSON: Well, let's see what happens...

NAVARRO: When you're talking about national security...

(CROSSTALK)

UNIDENTIFIED MALE: We don't know exactly what the...

(CROSSTALK)

NAVARRO: -- it is not political.

STEPHANOPOULOS: -- what the FBI is looking at right now.

I do want to move on to Donald Trump and the Republicans.

Right now, Nancy Gibbs, you sat down with him this week. He was on the cover of "Time" magazine. He's just about everywhere right now. And it certainly seems to be working so far, leading, you know, the lead, which a lot of people thought would dissipate, solidifying across the summer.

GIBBS: When you talk about politics like physics, with immutable laws, with him, everything that was supposed to sink him has lifted him instead. And -- and so I think the fascinating question now is not what he would or would not do if he were president. I think it's what he will and will not do in the...

(CROSSTALK)

STEPHANOPOULOS: -- can answer a lot of that.

GIBBS: (INAUDIBLE) answer a lot of that. And it's August.

Why -- why write the end of the story when what we're seeing is a fascinating change in the landscape that is affecting, obviously, the other Republican candidates?

It's affecting the conversation. It has many more people paying attention than we have ever seen at this stage of the race. That, which I think is all -- all to the good, to be having 24 million people tune into a debate is great and is amazing.

And so, you know, what I'm very interested in is, is he the only who can make the moves that he is making, say the things that he is saying? We have seen other candidates who go down the same road -- you know, when Jeb Bush uses the term anchor babies, he gets in much more trouble for it I think because people know that he knows that that's not a term he should be using and it makes him look disingenuous.

NAVARRO: He didn't use it as his own language, he was using it as a term of reference. So let's -- he's using it in a completely different way than Donald Trump was.

STEPHANOPOULOS: But he does seem to be playing -- held to a different set of rules, a different set of standards, but Matt, you've looked -- you're digging into the numbers a little bit. And you think there's a little bit less strength there than meets the eye.

BAI: Yeah, it doesn't take a lot of digging. And you did try to pin him down pretty well on what he's actually going to do, which I commend you for. You kind of got nowhere with him, but you tried right?

STEPHANOPOULOS: That's all you can do is ask the question.

BAI: I mean, look, I don't think we're reporting this with a lot of perspective. I get that it's a great story.

But, look, he has a finite plurality right now of the Republican electorate because he is the collision of entertainment and politics. He's a TV star and he's hit on a issue that brings out a great well of emotion in some segment of the Republican electorate.

But, look, the reason we talk about Donald Trump as winning solidifying a lead, winning among groups, is because the broad swath of the Republican electorate is divided among -- all the -- you know, everybody over the position of dog catcher is running for president. You've got more than 10 serious candidates, which means you know they are all dividing the field.

And right now nobody has stepped up...

STEPHANOPOULOS: But that's question, why can no one else consolidate any support?

LOWRY: Yeah, it's been remarkable. No idea, no policy proposal, no argument from the other candidates has caught fire the way Donald Trump has. And yes, Matt, I think you're right it's finite plurality, but every other candidate would kill to have that finite plurality right now.

And you have to believe the evidence of your eyes, 20,000, 30,000 people in Mobile, Alabama, he's generated a kind of enthusiasm we haven't seen in Republican primary politics in a very long time.

That's not New Hampshire. And part of this, we have to admit, is the media giving him so much (INAUDIBLE) that it's such a great story, that it's very hard for anybody...

STEPHANOPOULOS: There's no question about that, but the question is where does the energy go now that it has been unleashed. And, Ana, that's the question I want to bring to you, because there is this big debate going on, does he end up defining the Republican Party with some of these positions? Or do his rivals define themselves in opposition to him?

NAVARRO: Yeah, I think there's people who have different tacks that are running. Some of them are running toe with him, some of them are confronting him. And I -- you know, I think it's going to frankly depends on who ends being the nominee. If the nominee is somebody like a Jeb Bush, like John Kasich, like a Marco Rubio I think no he's not going to end up defining the Republican Party.

Now, if it ends up being, which I don't think is going to be the case, Donald Trump or somebody like Ted Cruz who has run very close to him, then we have a completely different perspective.

But I think -- look, I think Donald Trump has figured this out. He's got us all running in the Donald Trump hamster wheel. He says something controversial. We cover it. They make everybody else running react to it and we go from one controversy to another.

RICHARDSON: I've run for office for 30 years. Crowds, polls, that doesn't get the vote out. What gets the vote out is organization, get your base out. My prediction is this guy towards early in the Iowa caucuses flames out. He'll be a factor, but he won't win.

STEPHANOPOULOS: Who is positioning themselves best to pick up his votes if he does indeed fall.

BAI: Probably Ted Cruz. I think he's being underestimated. He very well could win Iowa. If he wins Iowa, he has much more resources and organization than the past winners of Iowa -- Rick Santorum and Mike Huckabee.

But I think one thing people underappreciate about Trump, this isn't just a right-wing phenomenon. If you look at his supporters, it's across the party. It's not just Tea Parties, it's moderates. So it could scatter in unpredictable ways if he does...

STEPHANOPOULOS: And Nancy when you sat down with him this week, and I've been getting the sense from him and his people that over the course of the summer they have been focusing more and more on what comes after Iowa and New Hampshire and South Carolina. And he's at least planning on being in for a real long time.

GIBBS: I mean, they've been taken -- we asked how surprised he was by this. It isn't just the political class that has been sort of shocked by what has happened. I think he is, too.

But, you know, this is -- it's really worth remembering that above all this is a very successful salesman. And what we are seeing right now is an act of salesmanship. I don't think this is about policy. As much as talk about the immigration plan -- I'm not sure he is fully aware of everything in the immigration plan. During our interview, some of the things he said weren't entirely aligned with what is actually in the white paper.

I think right now this is much more about the discontent people feel with everything about our political system. It isn't anger I think so much as discouragement. And they're willing to experiment. They're willing to experiment with someone who sounds very different than the last guy they experimented with, you know, which was Barack Obama who, too, came in...

LOWRY: I wouldn't underestimate the importance of the immigration issue, because this is the issue where the elites of both parties, Democrats and Republicans, are most out of touch with popular sentiment. And we're not going to deport everyone. We're not going to bring them back. Both sides of those equations are...

(CROSSTALK)

LOWRY: But he is sitting on something very important and is pulling the Republican field in a more populous direction on immigration, which I think is very helpful.

RICHARDSON: But it's going to cost election day with the Hispanic vote. 40 percent is what any Republican candidate needs to win the presidency. Mitt Romney talked about self-deportation, he got 23 percent. And I believe Donald Trump is, because of the Hispanic vote, is going to be so insulted by what he has said, and that's 11 percent of the vote, over 20 million voters.

BAI: Yeah, I mean, when Rich talks about what's driving the field, this is where I think the other Republican candidates really are making a mistake. They seem to think, and maybe driven somewhat by the media that they're consuming, they seem to think that they need to out-trump Trump to get his voters. That broad base of the Republican electorate, the votes they actually can get and should get, hasn't found a candidate. And they should be speaking, I think, to that constituency which can put them over the top instead of trying to get voters there, which may be...

(CROSSTALK)

NAVARRO: I don't think everybody is trying to out-trump Trump. I think there are candidates in this field who are confronting Trump.

STEPHANOPOULOS: That's going to be the last word today. We're going to be right back after this from our ABC stations.

(COMMERCIAL BREAK)

STEPHANOPOULOS: Before we go, I want to make sure you're tuned into ABC tonight. My “GMA” co-anchor and friend Robin Roberts has a special tonight, it's called “Katrina: 10 Years After The Storm”. That's at 10:00 Eastern.

And that is all for us today, thanks for sharing part of your Sunday with us. Check out “WORLD NEWS TONIGHT”. I'll see you tomorrow on “GMA.”