'This Week' Transcript: Donald Trump, Reince Priebus, Denis McDonough, and Sen. Mitch McConnell

— -- THIS IS A RUSH TRANSCRIPT FOR 'THIS WEEK' ON March 20, 2016 and it will be updated.

ANNOUNCER: Starting right now on This Week with George Stephanopoulos, March Madness: now just three GOP candidates left standing as Donald Trump continues his march to the nomination.

DONALD TRUMP, 2016 REPUBLICAN PRESIDENTIAL CANDIDATE: We have a movement going on, folks. I will never let you down.

ANNOUNCER: But with his rivals and his party rallying to stop him...

SEN. TED CRUZ, (R) 2016 PRESIDENTIAL CANDIDATE: We are seeing Republicans uniting behind this campaign.

ANNOUNCER: Could a contested convention take Trump down? We're one-on-one with Donald Trump only on This Week.

Plus, Hillary takes aim.

HILLARY CLINTON, 2016 DEMOCRATIC PRESIDENTIAL NOMINATION: We should be breaking down barriers, not building walls.

ANNOUNCER: Hitting the GOP front-runner. Is Clinton already gearing up for a nasty November clash.

And supreme showdown inside the war over the president's Supreme Court nominee.

From ABC News, it's This Week. Here now, chief anchor, George Stephanopoulos.

GEORGE STEPHANOPOULOS: Hello again. After another wild week in the race for the White House, it began with more big wins for Donald Trump, at least three states on Tuesday, the most delegates by far, moving him much closer to the Republican nomination.

But as his campaign marches toward Cleveland, Trump drawing more protests, too. Check out this scene from Arizona yesterday. The road to a Trump rally blocked. And there are new questions overnight about how Trump and his supporters are dealing with those protests.

In Tuscon, this protester punched and kicked as he was lead away by police.

(BEGIN VIDEO CLIP)

UNIDENTIFIED MALE: The guy grabbed the sign out of my hand as I was being escorted out of the building and sucker punched me.

(END VIDEO CLIP)

STEPHANOPOULOS: And in this video from CNN, Trump campaign manager Corey Lewandowski appears to grab the collar of another protester who is also being pulled back by a member of Trump's private security team. A lot to talk about this morning with Donald Trump. He joins us now by phone.

Thank you for joining us this morning, Mr. Trump.

You know, so we saw these incidents in Tuscon last night. What more will you be doing to stop your supporters from acting out like this?

TRUMP: Well, it's not only in Tuscon. I mean, we had a great rally right next to Phoenix, and it was an amazing, 21,000 people. But the protesters block the road. So you had thousands of people that couldn't get in. Sherriff Joe, who did a fantastic job, immediately arrested three people and the rally totally broke up. It totally broke up. The people that were protesting. And they left. And they went. And there was no more problem.

And everyone went in. We had 21,000. There wasn't one word during this massive rally. And it was beautiful.

STEPHANOPOULOS: But what about this violence, Mr. Trump?

TRUMP: Then -- well, then a little bit later on we went to other areas I mean, we went all over -- Frankly, we went all over Arizona. And we went to Tuscon and we had some people that wouldn't allow people for the rally into the door. They were making it almost impossible to get in. We had 6,000 or 7,000 people at least. We had 2,000 people outside. They wouldn't allow them in.

These people are very disruptive (inaudible). These are not innocent (inaudible).

STEPHANOPOULOS: ...punching and kicking a protester?

TRUMP: Well, you know, he was wearing -- he or his partner was wearing Ku Klux Klan outfit. This happened to be an African-American man who was very -- person at the rally who was very, very insensitive to the fact that somebody, a protester, would be wearing a Ku Klux Klan outfit. And he went...

STEPHANOPOULOS: You appear to be excusing the kicking and punching, there.

TRUMP: Frankly, you know, it was a tough thing to watch. And I watched that.

But why would a protester walk into a room with a Ku Klux Klan outfit on?

STEPHANOPOULOS: Well, it looked like he was wearing an American flag right there. But does that justify...

TRUMP: Well, if you would have seen him just before he went up the stairs, him and his partner were wearing -- one of them was wearing a Ku Klux Klan outfit.

STEPHANOPOULOS: So, you're not going to condemn the protester who kicked and punched that person?

TRUMP: We don't condone violence. And I say it. And we have very little violence, very, very little violence at the rallies.

As I said in Phoenix we had 21,000 people. We had -- we didn't even have anybody stand up and try and disrupt. You know, they're disrupters.

And they're really stopping our first amendment rights. If you think about, George, they blocked the road. They put their cars in front of a road. We had thousands and thousands of people wanting to come. They were delayed for an hour because of these protesters. And, you know, at what point do people blame the protesters? These are people that are...

STEPHANOPOULOS: So, you're blaming the protesters, not the person who actually punched and kicked the protester?

TRUMP: No, I'm saying this, these are professional agitators, and I think that somebody should say that when a road is blocked going into the event so that people have to wait sometimes hours to get in, I think that's very fair, and they should be blamed there, too.

When signs are put up, lifted up, with tremendous profanity on them. I mean the worst profanity. and you have television cameras all over the place. And people see these signs. I think maybe those people have some blame and should suffer some blame also.

STEPHANOPOULOS: Well, you also -- we've also seen that video there of your campaign manager, Corey Lewandowski, who does appear in that video to grab the collar of the protesters also as your private security. Why is your campaign manager out in the crowd engaging protesters? This is the second incident in about a month.

TRUMP: You know what, because the security at the arena, the police were a little bit lax and he had signs, they had signs up in that area that were horrendous, that I cannot say what they said on the sign. But the ultimate word. And it was all over the camera. And frankly the television cameras can't take it and they can't do anything about it.

And I will give him credit, spirit -- now he didn't touch. He wasn't...

STEPHANOPOULOS: Well, the video there showed that he touched him. Your private security pulled him...

TRUMP: That was somebody else pulling him. I mean, I get -- I give him credit for having spirit. He wanted them to take down those horrible profanity-laced signs.

Look, these are disrupters. They go into a room with 20,000 people or they go into a room with 6,000 or 7,000 people and they stand up and they start shouting things. And they -- I mean, at some point, somebody should say -- I will say this, Sheriff Joe Arpaio in Phoenix arrested three people. As soon as he arrested those three people, everybody else immediate left.

STEPHANOPOULOS: Well, but it -- and it is the job of the police to arrest protesters who are being disruptive if they are, indeed...

TRUMP: Well, that happened. That happened...

STEPHANOPOULOS: But you appear to be more...

TRUMP: It happened in the Phoenix area, it didn't happen in Tuscon.

STEPHANOPOULOS: You appear to be much more upset by the protesters than by the violent response to those protesters.

TRUMP: I am very -- I wouldn't use the word upset. I think it's very unfair that these really, in many cases professional, in many cases sick, protesters can put cars on a road blocking thousands of great Americans from coming to a speech and nobody says anything about that. But they'll say something about whatever.

I will tell you...

STEPHANOPOULOS: Kicking and punching a protester.

TRUMP: -- it's a very unfair -- it's a very -- let me just tell you, it's a very unfair double standard.

Why don't you mention the fact that people were delayed for an hour to get into an arena and the only road going there that they were delayed for an hour because people were blocking the road?

And why don't you say, in Tucson, where the people were blocking the main entrance into the arena?

It's very unfair.

STEPHANOPOULOS: We showed that blocking right at the top of the broadcast.

But let me -- let me move on, because this comes on the heels of you saying this week there could be riots in Cleveland if you entered the Republican Convention with more delegates than anyone else but didn't end up with the nomination.

John Kasich called that outrageous. Speaker Paul Ryan has called you out on it, as well.

Did you go too far there?

And if you don't have the 1,237 delegates going into Cleveland, why should you be guaranteed the nomination?

TRUMP: Well, I think if I'm a few short and I have, you know, 1,200 or if I have 1,100 and somebody else is at 300 or 400 or 500, which is very likely going to be the case, and if I'm a little bit short -- and one of the reasons was we had so many candidates. I mean we started off with 17 candidates. And it came down to, you know, finally, it's down to three, frankly.

But, you know, there are so many candidates, so it's very hard to get over that number. It's very unfair, in a we are -- but because of the fact that there's so many candidates and so many candidates are grabbing delegates.

Now, here's what I say, because -- and now they're out. And now they're out.

So I think I will get over that number. I think I may get over that number fairly easily. Arizona was unbelievable yesterday. Utah, frankly, was unbelievable the day before. I think we will get over that number. There's tremendous spirit about make America great again. I mean that's the whole thing. We're going to make America great again...

STEPHANOPOULOS: But if you don't...

TRUMP: -- I will say this...

STEPHANOPOULOS: -- there's nothing unfair about having...

TRUMP: -- George...

STEPHANOPOULOS: -- a multi-ballot convention...

TRUMP: -- I think...

STEPHANOPOULOS: -- is there?

TRUMP: -- the biggest story in all of politics are the millions of people that are coming out to vote for me, in all fairness, for the Republican Party. They're up 75 percent, 72 percent, 102 percent, different states in the primaries. And it's the single biggest story worldwide in politics, is what's happening, the millions and millions of people that are going out to vote for me.

Now I will say this, the Democrats are down 35 percent, whereas the Republicans are up over 70 percent. And in some cases, much more than that.

So I say this. If you're going to disenfranchise all of those people, some of whom have never voted before and they're 50 years old and older, but if you're going to disenfranchise all of those people, Independents, Democrats -- you know, we have a lot of Democrats coming over. We have a lot of Independents coming over...

STEPHANOPOULOS: It's OK for them to riot?

TRUMP: -- and we do have some people that have -- we do have some people that have never voted before.

I don't know what -- I didn't say -- I -- all I can say is this, I don't know what's going to happen. But I will say this, you're going to have a lot of very unhappy people. And I think, frankly, for the Republicans to disenfranchise all those people, because if that happens, they're not voting and the Republicans lose. If they -- if the Republicans embrace these great people that are showing up, the Republicans are going to have a massive victory. It's not going to be a Mitt Romney slaughter, because he was such a bad candidate.

The Republicans are going to have a massive victory in November. I can tell you that, George.

STEPHANOPOULOS: But will you tell your -- will you tell your supporters not to riot if you lose the convention fair and square?

TRUMP: Well, I would certainly tell them that, but, you know, look, these people are -- are fervent. They are really -- they want to see positive things happen for our country. And I would certainly say that. I don't want to see riots. I don't want to see problems.

But, you know, you have -- you have millions of people who we're talking about, George, millions of additional people have gone. You know, I've gotten more than two million votes more than anybody else. Two million votes more than anybody else. And these are millions of -- and that's why I'm leading by so much...

STEPHANOPOULOS: You know, you have -- you have conservative...

TRUMP: -- you have 21 or 22 states.

STEPHANOPOULOS: -- you have conservatives talking about the possibility of a third party challenge, if, indeed, you do get the nomination in Cleveland, talking about recruiting someone like Senator Tom Coburn.

How worried are you that that would cost the election?

And have you done anything to try to head that off?

TRUMP: Well, if that -- now, look, if they're going to do that, they're going to do that. But then you might as well just hand the election to Hillary Clinton or whoever runs, because frankly, the Republicans wouldn't even have 1 percent of a chance of winning if that's the case. So if they're going to be stupid and if they're going to do that instead of embracing these millions of people that are coming in to vote, then they're going to have to do that.

And I'll tell you what that's going to mean, more than any other thing. It's going to mean four or five justices, super liberal, placed on the Supreme Court. Our country will never, ever be the same.

STEPHANOPOULOS: Over the weekend, you appeared to question the faith of Mitt Romney. And this is the third time in the campaign something like that has happened.

I want to play the statements for our viewers right here.

(BEGIN VIDEO CLIP)

TRUMP: I can't believe -- are you sure he's a Mormon?

Are we sure?

I'm Presbyterian. I mean Seven Day Adventists I don't know about, I just don't know about.

I've never seen anybody that lied as much as Ted Cruz. And he goes around saying he's a Christian. I don't know, you're going to have to really study that.

(END VIDEO CLIP)

STEPHANOPOULOS: You know, after the pope spoke out about you, you said that no leader should question another person's faith, so why do you keep on doing it?

TRUMP: Well, with Mitt Romney -- first of all, with Mitt Romney, I was saying to the Mormons -- the Mormons are very smart people, and I said it in a joking way, but they can take it any way -- you can take it any way you want. The Mormons are very smart people. I know many Mormons.

I don't think Mitt Romney is a smart person. I never have thought he was a smart person. But the Mormons are very smart people.

So I said, are you sure he's a Mormon?

And I'm not going to change it, because I think Mitt Romney has proven to be not a smart person.

As far as Ted Cruz, he's one of the greatest liars and biggest liars I've ever known. He lies about so much. He lies about things that he shouldn't be lying about. He lies about things that don't matter.

So I tell people. And I think that's why Ted Cruz has lost the Evangelical vote.

Look what he did with Ben Carson, who's endorsed me, a great guy. Look what he did to Ben Carson. He said that Ben Carson in Iowa has left, he's out of the campaign, vote for me. Thousands of people voted for him because he convinced people that Ben Carson had left the campaign.

He knew Ben Carson did not leave the campaign.

STEPHANOPOULOS: Well, that sounds -- it sounds like you're not backing down on that at all.

Tomorrow, a big speech -- you have a big speech tomorrow, speaking to the American-Israel Public Affairs Committee.

In that speech, will you stand by your pledge to be neutral between Israel and Palestine so you can broker a peace deal?

TRUMP: Well, you're going to hear what I'm going to say at the speech and I'll save it for that. There is nobody more pro-Israel than I am. But you'll hear what I say at the speech and we'll see what happens.

STEPHANOPOULOS: What kind of a deal would be in Israel's interests?

TRUMP: I think making a deal would be in Israel's interests. I'll tell you what, I don't know one Jewish person that doesn't want to have a deal, a good deal, a proper deal, but a really good deal. But I would say it's probably one of the toughest deals -- me being a dealmaker, it's probably one of the toughest deals in the world to make, because there's just so many -- there's just so many decades of hatred between the two sides. It's probably one of the toughest deals to make, if you're a person that prides yourself on being able to get people together.

STEPHANOPOULOS: So what does a good deal look like, though?

TRUMP: But I think it's something...

STEPHANOPOULOS: Will -- will...

TRUMP: -- I -- I think it's something...

STEPHANOPOULOS: -- Israel have to give up some land?

TRUMP: -- that we should try very hard to get. And I don't know any Jewish people that don't want to make it. They'd all love to see a deal made. Now, they want to have a good deal, not an Obama-type deal. They want to have a good deal made.

STEPHANOPOULOS: Define a good deal.

TRUMP: Well, I'll define that tomorrow, because I'll be defining it tomorrow. I'm not going to define it now. I'm not going to define it tomorrow.

But we would like to see, and everybody would like to see a real deal be made, not a deal that's going to be broken, a real deal being made, something that can be lasting.

And I -- if I win, I'm going to be giving that a very good shot.

STEPHANOPOULOS: Mr. Trump, thanks for joining us this morning.

TRUMP: OK.

Thank you very much.

STEPHANOPOULOS: Let's get more on this now from the chair of the Republican National Committee, Reince Priebus.

Mr. Priebus, thank you for joining us this morning.

REINCE PRIEBUS, CHAIRMAN, REPUBLICAN NATIONAL COMMITTEE: Good morning.

STEPHANOPOULOS: You just heard that interview with -- with Mr. Trump.

He certainly seemed to be much more interested in explaining and excusing the violence against protesters than in condemning it.

Has he done enough to contain the violence at his rallies?

PRIEBUS: Well, look, I mean, I think he's trying to make the point that we want to talk about both sides. But clearly both sides need to condemn violence.

And violence is never the answer. And I think as far as everyone getting involved in the crowds, leave it to the professionals. I mean, the sheriff there was in the crowd and Secret Service is there and that's their job to do it. And I think that's the best place to leave it.

So look, violence is never the answer. Condoning violence is never the answer. It's not what we're about and I think -- I think everyone agrees with that.

STEPHANOPOULOS: Everyone agrees with it. But what have you told -- I know you speak with the Trump campaign and Mr. Trump himself.

What have you told him about this?

This is not the first time it's happened. We're seeing this happen again and again and again.

PRIEBUS: Well, I mean we've talked a little bit about it and obviously they agree that violence is not the answer and that they don’t condone it and that they tell the crowds that they don’t condone it.

So look, it's obviously not completely in my control what happens at these rallies and what people say and do. But I'd leave it to the professionals and I would continue to talk about the fact that we need to have a solutions-based campaign and not obviously something that, you know, creates an environment that violence is present --

(CROSSTALK)

STEPHANOPOULOS: So when you say leave it to the professionals --

PRIEBUS: -- I don't think --

STEPHANOPOULOS: -- when you say leave it to the professionals --

PRIEBUS: Yes, I think --

STEPHANOPOULOS: -- does that mean then the campaign manager should stay -- should stop engaging protesters?

PRIEBUS: Look, you know, I don't know all the circumstances, George. You know, I'm just sitting here this morning, just like you. I haven't talked to them about it. Obviously my point would be leave those things to the professionals. Don't get involved in crowds and those altercations and that's why the pros are there.

STEPHANOPOULOS: Let's talk about this possibility of a contested convention. You used to call it an extreme hypothetical.

Is that still the case?

(LAUGHTER)

PRIEBUS: Probably not still the case, no. I think it's possible and we're preparing for that possibility. And I think it's my job is to be as open and transparent as I possibly can be. That's why I'm trying to get out there on the convention a lot, out in the media and talk about what the rules are and what they're not and take the mystery away from what an open convention looks like because it really is pretty simple stuff.

STEPHANOPOULOS: Well, let's take some of the mystery away right now. You heard Mr. Trump on this idea that if he got really close to the 1,237 but didn't get there, his supporters would be very angry, said he didn't want them to riot but they're going to be very angry and the Republican Party would lose if he were then denied the nomination.

The simple yes or no question, is it fair if he goes in without 1,237 but with a plurality for the convention to deny him the nomination?

PRIEBUS: Well, plurality is a minority and a minority doesn’t choose for the majority. So you have to have a majority of the delegates in order to be the nominee. There's nothing magical about the number. It's 50 percent plus one. So no one's disenfranchised.

In fact, they're enfranchised by receiving bound delegates based on the outcome of the elections. And so that's all it is. And so you have to have a majority in order to be the nominee of our party. It's no different than when I became chairman of the party. I won on the seventh ballot, George, hardly a landslide. But I was never behind. But no one called me the winner on the second, third, fourth or fifth ballot. I had to get to a majority.

Most state chairmen out there across the country go through this same process on the floor of conventions. So that's why to us it seems natural that you'd have to have a majority of your party.

So yes, that's the person I want to be the nominee. There's nothing wrong with that.

STEPHANOPOULOS: Can you guarantee that the nominee will be one of the three candidates in the race right now?

PRIEBUS: Well, I mean, I think it would be highly unlikely if it's not. You know, that -- I can tell you that. I think it would somewhat very unusual. But you know, I can't 100 percent guarantee that. But I can't imagine right now sitting here believing it would be anyone but the three remaining candidates.

STEPHANOPOULOS: And finally, what do you say to that Stop Trump movement, talked about in "The New York Times" this morning, the possibility of recruiting a third-party candidate like Senator Tom Coburn or maybe even Governor Rick Perry of Texas?

Will that doom your chances as Mr. Trump says?

PRIEBUS: Well, sure it would. Of course it would. But I also think it's far too late. I think this is -- it's somewhat -- some folks find it to be interesting and that's great. But it isn't likely and it's probably too late and there is no definitive answer right now as to who the nominee is going to be of our party.

So I think all of it's far too early, George.

STEPHANOPOULOS: Mr. Priebus, thanks for joining us this morning.

PRIEBUS: You bet. Thanks.

STEPHANOPOULOS: Powerhouse roundtable is next.

(MUSIC PLAYING)

STEPHANOPOULOS (voice-over): And later, President Obama has made a state for the Supreme Court. This time is that the end of the process instead of the beginning? That debate with the White House chief of staff, Denis McDonough and Senate majority leader Mitch McConnell.

(BREAK)

STEPHANOPOULOS: And we're back now with the roundtable, joined by Roland Martin, host and managing editor of NewsOne Now; Republican strategist Sara Fagen, also with CNBC; Rich Lowry, the editor of "The National Review," and from "The Washington Post," E.J. Dionne, also the author of a new book "Why the Right Went Wrong." We see it right there.

Welcome to all of you.

Rich Lowry, let me begin with you. You were an early leader in the Stop Trump movement. You're -- "The National Review" had that cover story.

So is this the end of the Stop Trump movement or is it just getting started?

RICH LOWRY, EDITOR, "THE NATIONAL REVIEW": Just the beginning, George.

(LAUGHTER)

LOWRY: We will be like the last Japanese soldier in the jungle resisting this guy.

Look, the paradox of Trump is he's obviously much stronger than the other candidates, but he's not strong enough to unify the party. And every time we hear about how he's going to turn to be more unifying or presidential, there's some contemptible statement or act, whether Trump, a week or so ago, saying he might consider paying the legal bills of this goon who sucker-punched the protester, or Trump playing around with the idea of rights at the convention.

So he might get the 1,237. It's quite possible. But it's also quite possible that he's going to fall short.

STEPHANOPOULOS: But Sara Fagen, it seems to me, from talking to Mr. Trump this morning, he's calculating that the way he's talking about this violence is perfectly fine for him.

SARA FAGEN, REPUBLICAN STRATEGIST, CNBC CORRESPONDENT: It's pretty amazing to me. I mean this seems like a no-brainer. You condemn it, you condemn it strongly, you condemn both sides of it. And, you know, he -- the one thing he's right about is there does appear to be some element that are Trump supporters or supporters of other Republican candidates who are showing up at his rallies to stir the pot. He's right to point that out.

But he needs to very emphatically condemn all of this violence and he should never speak of riots.

ROLAND MARTIN, HOST/MANAGING EDITOR, NEWSONE NOW: But he -- he's not going to condemn it because it is his brand not to backtrack. I mean this is a desire to be thug-in-chief. And so he's not going to criticize them. When he attacked Senator John McCain, when he attacked Carly Fiorina, when he attacks anyone, in his mind, oh, if I say I'm sorry, if I backtrack or I tell people to tamper down, then I'm hurt by it.

So he's done this throughout the entire campaign. We shouldn't be shocked.

FAGEN: It's -- it's a poor short-term strategy. It may work for some cheers at a rally. But Americans want a president that is the best and brightest of the nation. And right now, he is anything but that.

MARTIN: He won't even condemn his campaign manager. You see it. He pulled the guy's collar. Well, you know, he goes out there because the security hasn't done their job.

FAGEN: It's a great point.

MARTIN: Really?

STEPHANOPOULOS: Is this going to...

(LAUGHTER)

STEPHANOPOULOS: -- how is this going to play out, though, over the course of the next several weeks and months and in a general election campaign?

Will -- is it possible he'll get more sympathy if these protests continue?

E.J. DIONNE, "THE WASHINGTON POST": I think there's a way in which he can keep trying to turn the protests to his advantage within a certain part of the Republican base. And I think that's his calculation. And other politicians have done this in the past.

But I think that when you look at the polls about a general election, there is great reason for Republicans to be petrified of a Trump nomination, particularly among women. In a "Washington Post"/ABC Poll, Hillary Clinton had a 21 point lead among women voters.

And so I think all the Republicans trying to stop him look at those numbers and say we could lose everything we've got.

STEPHANOPOULOS: Before we -- before we get to the general, let's talk a little bit more about this Stop Trump movement.

So you're -- you're saying it's just the beginning.

How -- what is the path to preventing Donald Trump from getting 1,237?

LOWRY: Well, Ted Cruz needs to improve. And if Cruz were to win all of Utah's delegates, that would happen. That seems quite plausible. If Ted Cruz were to pull off an upset and win Arizona, that would be huge. That seems...

STEPHANOPOULOS: That's less plausible.

LOWRY: -- that seems unlikely. But Wisconsin, I think, is the next big battleground. If Ted can stop Trump there, that's a big deal.

But if Trump wins there, we're going to see a lot of these rats in the form of Republican elected officials scurrying onto the ship. And as soon as it seems as though it's sinking in a general, they'll scurry right back off.

STEPHANOPOULOS: Let me begin in Sara Fagen in on that.

It does appear that the campaigns really are targeting Wisconsin.

FAGEN: Yes.

STEPHANOPOULOS: And I think the Cruz campaign is banking on the fact that if they can win there, that will force John Kasich to drop out and finally you have that one-on-one race they've been looking for.

FAGEN: Well, all these candidates are going to get delegates in Wisconsin because of the hodge-podge of rules that each of these states has. You know, Wisconsin is winner take all statewide and then winner take all by Congressional district. So it's unlikely any candidate is going to win all of the delegates.

However, you make a -- a valid point, which is as these contests start to move to the closed phase (ph) primaries, where all of these various rules -- if Kasich and Cruz together can work together to prevent Donald Trump from getting to 1,237, then we get to this open convention and someone has a chance to...

LOWRY: But that's not happening.

(CROSSTALK)

LOWRY: Kasich is playing a selfish and delusional role here. There is no way a contested convention is going to turn to the guy whose third in delegates and it's probably unlikely, given the rules, his name will even be put in the nomination...

(CROSSTALK)

STEPHANOPOULOS: If he doesn't win eight states.

(CROSSTALK)

LOWRY: -- ads in Utah...

(CROSSTALK)

FAGEN: That -- that rule will likely change.

(CROSSTALK)

MARTIN: This crisis of conscience among conservatives is just stunning as you watch this. I mean for 30 years as an adult, I've watch -- I've heard Republicans say we're principled, it's morals, it's values, it's -- it's beneath our principles. And to see this struggle as how -- well, what do we do that's going against it, I mean I think about the German theologian, Dietrich Bon -- Bonhoeffer, who chose to join the alliance and say we're going to kill Hitler.

I think about Dr. King, who chose to combat LBJ on Vietnam.

It's -- it's going to be fascinating to watch folks say wait a minute, I'm principled and I have conviction...

(CROSSTALK)

MARTIN: -- but I'm going to...

(CROSSTALK)

STEPHANOPOULOS: But the way...

(CROSSTALK)

MARTIN: -- for this guy.

STEPHANOPOULOS: -- because E.J. Dionne...

(CROSSTALK)

STEPHANOPOULOS: -- you are seeing some conservatives, we saw Ted Co -- I mean Senator Coburn quoted in "The New York Times" this morning, Rick Perry quoted in the "New York Times" saying it would be better to lose the White House, for Republicans to lose the White House, than to win with Donald Trump...

UNIDENTIFIED MALE: Wisconsin.

STEPHANOPOULOS: -- at the head of the ticket.

DIONNE: You know, this -- everybody is talking about the 1860 convention as a metaphor. I think this looks either much more like 1964 or 1912, where a lot of Republicans who are on the conservative side preferred to see Teddy Roosevelt's third party candidacy fail and get clobbered in the election to live to fight another day.

In 1964, what's odd here is the party has moved so far to the Right in '64 that what you've got now is moderate conservatives or I tell you, pretty conservative conservatives. Ted Cruz is no moderate -- saying Donald Trump is too extreme for the Republican Party.

So there is some principle here. But there are multiple principles at stake. Some conservatives don't like Trump because they don't think he's a real conservative. Others oppose him because of some of the --

(CROSSTALK)

STEPHANOPOULOS: -- who is a conservative. If Donald Trump gets the nomination, can you support him?

LOWRY: We're not there yet. We'll have to wait and see if he actually wins the nomination and take a cold-eyed look at it because it'll be a big institutional decision for us.

But there should be a third-party candidate because some Republicans and conservatives want a place to park their vote in good conscience. But the name of the game --

(CROSSTALK)

STEPHANOPOULOS: That means Republicans lose, right?

LOWRY: -- the name of the game is stopping him from getting the nomination because everything after that is just managing --

(CROSSTALK)

FAGEN: -- that's why the smartest thing for Ted Cruz and John Kasich, neither of whom have a likely path to walking into this convention with the requisite delegates, should work together and stop this guy from getting the delegates and then they have a chance or someone else has a chance who can possibly carry the --

(CROSSTALK)

FAGEN: -- you can't make them do that but this is why we're in the situation we're in, is because they're all shooting at each other. The highest priority for Republicans right now needs to be to stop Donald Trump.

MARTIN: (INAUDIBLE) both of you, would you rather lose than to have Trump in?

FAGEN: I don't -- we truly not like to see the Republican Party lose. But I think the difference between Ted Cruz as our nominee and Donald Trump as our nominee --

MARTIN: I'm saying if Trump is your nominee.

FAGEN: -- the difference between Ted Cruz as our nominee and Donald Trump is Ted Cruz may lose a general election but the party moves up to fight a different day.

Donald Trump fundamentally transforms --

STEPHANOPOULOS: -- incredible that you both have to think about it --

(CROSSTALK)

DIONNE: It's also amazing that if you win -- you started the year, there were two candidates, most of the Republican leadership absolutely didn't want to win the nomination. Donald Trump and Ted Cruz. And now to paraphrase Lindsey Graham, they're really --

(CROSSTALK)

STEPHANOPOULOS: I'm afraid that's all we have time for right now of this conversation is going to continue at least for a few more weeks.

When we come back, the battle for the Supreme Court. President Obama's made his choice.

But will Merrick Garland even get a hearing?

How will that change this campaign?

The White House chief of staff and the Senate GOP leader are next.

(BREAK)

STEPHANOPOULOS: And now the answer to our "Powerhouse Puzzler." The first Instagram from Pope Francis is simple, "Pray for me," in nine languages. Here's Instagram CEO, Kevin Systrom.

(BEGIN VIDEO CLIP)

KEVIN SYSTROM, INSTAGRAM CEO: The whole theme of the account is mercy and tenderness and those are his two key themes and the message he wants to get through with every image and video that he posts on the account.

(END VIDEO CLIP)

(BREAK)

STEPHANOPOULOS: There is President Obama with his Supreme Court pick, Judge Merrick Garland, in the Rose Garden this week. It was an emotional announcement. But Senate Republicans are unmoved, saying there is no way Garland will even get a hearing before the election.

We're going to hear from Senate Leader Mitch McConnell and White House Chief of Staff Denis McDonough after this report from ABC's Terry Moran.

(BEGIN VIDEOTAPE)

BARACK OBAMA, PRESIDENT OF THE UNITED STATES: Good morning.

TERRY MORAN, ABC NEWS CORRESPONDENT (voice-over): After weeks of waiting, President Obama delivered a surprise -- Merrick Garland, a 63-year-old white male judge with a centrist reputation and a 20 year track record.

UNIDENTIFIED MALE: A question now occurs on the nomination of Merrick Garland to the D.C. Circuit Court of Appeals.

MORAN: It's safe to say that's not what Washington was expecting.

Garland's got the resume -- Harvard Law, a corporate law firm, federal prosecutor in charge of the Oklahoma City bombing case.

UNIDENTIFIED FEMALE: -- Merrick Garland...

MORAN: It won't get him anywhere with Senate Republicans. The majority leader instantly reiterating it's the next president's pick.

SEN. MITCH MCCONNELL (R-KY), MAJORITY LEADER: Let's let the American people decide.

MORAN: In an interview with NPR, Obama shot back.

OBAMA: Well, in fact, the American people did decide, back in 2012, when they elected me president of the United States.

MORAN: And so let the games begin. Judge Garland headed to the Hill this week. Here he is meeting with Democrats Thursday. Some swing state Republicans up for reelection say they'll sit down with him, too. Only a few are open to actually holding a vote before November.

But could there be a lame duck confirmation?

What if Hillary Clinton wins the White House?

UNIDENTIFIED MALE: I would rather have a less liberal nominee, like Merrick Garland, than a nominee that Hillary Clinton, if she were president, would put forward.

MORAN: A final twist -- the president may have public opinion on his side. Americans, by 63-32 percent, said the president's nominee should get a hearing.

But in this election year climate in Washington, don't hold your breath.

For THIS WEEK, Terry Moran, ABC News, Washington.

(END VIDEO TAPE)

STEPHANOPOULOS: Thanks to Terry for that.

We're joined now by the White House chief of staff, Denis McDonough.

Mr. McDonough, thank you for joining us this morning.

So the president has made his choice for the Supreme Court.

But have you seen anything this week that makes you think the Senate will actually give Judge Garland a hearing and a vote?

DENIS MCDONOUGH, WHITE HOUSE CHIEF OF STAFF: Well, we're happy to see, obviously, the resounding support for Judge Garland, an unbelievable -- unbelievably strong, unquestioned excellence as a judge for the last 18 years on the second highest court in the land and somebody who's dedicated his life to the law.

We've seen some good progress, some good forward momentum. We have about Republican senators who have now indicated that they'll meet with him.

As you know, before we announced him, people were saying they would not even deign to meet with him. And we're also aware that early in the week, when the Congress comes back, in fact, Senator Collins, the Republican from Maine, has agreed to meet with Judge Garland up in the Senate.

So we think this is a very good progress, good momentum. We think it is consistent with the long -- decades long practice and precedent of handling Supreme Court justice nominations this way. So we feel good about where this is headed.

STEPHANOPOULOS: We're also seeing the opposition ramp up, as well, including ads by the Judicial Crisis Network against some Democratic senators, as well as Republicans, this one against Senator Heitkamp of North Dakota.

(BEGIN VIDEO CLIP)

UNIDENTIFIED FEMALE: The right to bear arms, the future of energy production, knowledge is freedom. They're all at stake. The Supreme Court will preserve or end this way of life. Senator Heitkamp and President Obama want to take the future of the court out of your hands. Tell Senator Heitkamp and President Obama no.

(END VIDEO CLIP)

STEPHANOPOULOS: They say the people should choose.

Your response?

MCDONOUGH: Well, the people have chosen. The president was elected overwhelmingly, resoundingly, in 2012, and people elected him to a four-year term.

You know, George, I'm not surprised, given what's happening in Washington these days, to see that the special interests are kind of pouring a lot of money into this thing. And what we don't want to see happen is have these unelected special interests determine the fate of somebody who is a very patriotic man, somebody who's dedicated his life to the protection of law in this country, have thrum determine the outcome of this.

There's a way that this -- these things get handled. If people have questions about the judge's position's and the judge's remarkable experience, including prosecuting Timothy McVeigh, prosecuting the Unabomber, then they should have hearings, they should vote in a committee and then they should vote in the Senate to make sure that he can assume his seat on the Supreme Court.

STEPHANOPOULOS: The Senate does also have a right not to act. And if the Senate fails to act before the election, would President Obama like to see Judge Garland confirmed in a lame duck session?

Some Republican senators, like Jeff Flake, have said that confirming Garland would be preferable to giving Hillary Clinton a pick, if she is indeed, the Democratic nominee and she wins?

MCDONOUGH: You know, George, the -- the average length from nomination to confirmation of a Supreme Court nominee turning into a justice is 67 days. We have more than enough time to get that done between now and even the early adjournment that we understand the Senate plans this year. They plan to -- to adjourn early in July, rather than traditionally in August.

So we think there's plenty enough time to get that done before the election. We think that the court would benefit from having its full number of justices. And we think that, frankly, it would be unprecedented for the Senate to do otherwise.

STEPHANOPOULOS: But there's a lot of indication that it's not going to happen.

So my question is, what about a lame duck session?

Would you like to see Judge Garland confirmed in a lame duck session, if it comes to that?

MCDONOUGH: George, what we'd like to see is to see Judge Garland confirmed pursuant to regular order. You recall, I bet you remember this op-ed that was in "The Wall Street Journal" the day after the election in the fall of 2014, George, when Senator McConnell and Speaker Boehner at the time said now we can get Congress working again.

And, in fact, one of the things that the majority leader, Senator McConnell, committed to what getting the Senate working again.

Well, getting the Senate working again would mean giving this person meetings, a hearing, a voting committee and a vote on the floor. That's the way it's been done and to do otherwise would be absolutely unprecedented. We think that's a mistake. We think it ultimately risks politicizing the Supreme Court. There's enough politicization in Washington. Let's get on with our business.

STEPHANOPOULOS: And, finally, before we go, I want to ask you about Donald Trump.

We just heard him. You saw that violence overnight at his rallies again. He appears to say that the protesters should be bearing much of the blame there, as well.

I wonder your response to Mr. Trump.

And how is the president planning to speak out about that over the course of this campaign?

MCDONOUGH: I don't have a response to Mr. Trump, George. But the president gave very powerful remarks up in the House at the speaker's lunch for the Saint Patrick's Day reception with the taoiseach of Ireland, the prime minister of Ireland, where the president called on all sides to get back to the kind of very peaceful kind of robust debate that has marked this country and has made this country the envy of the world.

That's exactly what we should be doing. And I'm not seeing a lot of that from the other side at the moment.

STEPHANOPOULOS: Denis McDonough, thanks for joining us this morning.

MCDONOUGH: Thanks, George.

STEPHANOPOULOS: Let's bring in now the Senate Republican leader, Mitch McConnell.

Senator McConnell, thank you for joining us this morning as well. You just heard Denis McDonough right there, saying, quoting you from your op-ed after the president was elected, saying the Senate's going to get back to work. He thinks the Senate should get to work and provide a hearing and a vote for Judge Garland.

Any chance that's going to happen this year?

SEN. MITCH MCCONNELL (R), MAJORITY LEADER: Well, the Senate has been very much at work for the last 15 months. We've passed a lot of legislation that the president has signed and it should -- president's chief of staff knows we're very much at work.

Look, the way Supreme Court justices have been handled in presidential election years is very clear. It's been 80 years since a vacancy created in a presidential election year was filled. You have to go back to 1888, Grover Cleveland was in the White House, to find the last time a vacancy created in a presidential year on the Supreme Court was confirmed by a Senate controlled by the party different from the president.

So we know what the tradition is. Joe Biden in 1992, when he was chairman of the Judiciary Committee, laid down the Biden rule. He said when the campaign is underway, no Supreme Court judge would be confirmed.

And in 19 -- in 2005, Harry Reid said, under the Constitution, the Senate doesn’t even have an obligation to give a vote to a nominee and Chuck Schumer, who will be the Democratic leader next year, said 18 months before the 2008 election the Democratic Senate would not confirm a Supreme Court vacancy.

So the tradition has been in a presidential election year that the next president after the American people have weighed in gets to make the decision.

STEPHANOPOULOS: Well, there haven't been that many examples. But you're saying clearly there will be no hearing, no vote for Judge Garland this year?

MCCONNELL: That's right.

The principle is the American -- look, George, the American people are in the middle of choosing who the next president is going to be. And that next president ought to have this appointment, which will affect the Supreme Court, for probably a quarter of a century.

STEPHANOPOULOS: But they elected President Obama.

MCCONNELL: But the last time the American people voted was in 2014 and they elected a Republican Senate. And under the Constitution, we have shared responsibility. This is not something he does alone. He nominates; we confirm. The last time the American people spoke in 2014 they gave us nine additional net seats and we took over the U.S. Senate.

STEPHANOPOULOS: One of your Republican senators, Mark Kirk, spoke out on it this week. He said the Senate should vote. Listen.

(BEGIN VIDEO CLIP)

SEN. MARK KIRK (R), ILL.: Just man up and cast a vote. The tough thing about these senatorial jobs is you get yes or no votes. Your whole job is to either say yes or no and explain why.

(END VIDEO CLIP)

STEPHANOPOULOS: And confident you're going to hold Republicans together?

MCCONNELL: Well, look, Mark Kirk is a great senator. He's running this year in Illinois. I'm confident he's going to get reelected. But the schedule in the Senate is set by the majority leader. And most of my members are very comfortable with letting the American people make this decision by electing the next president who will fill this vacancy next year.

STEPHANOPOULOS: Let me move on. On Tuesday, you said you told Donald Trump that he should condemn and discourage violent acts during the campaign. Twenty-four hours later, he said that statement about thinking there would be riots at the GOP convention denying him the nomination.

You heard him this morning on the violence as well.

Are you worried that he's not getting your message?

MCCONNELL: Well, regardless of who the candidate is, I think all the candidates for president ought to be discouraging that kind of activity because the people in the audience tend to listen to those who are speaking.

And I think we ought to condemn this kind of violence and encourage the American people to engage in this political debate in a respectful way.

STEPHANOPOULOS: Couple weeks ago in "The New York Times," they reported -- I want to show it right here -- that you have begun preparing senators for the prospect of a Trump nomination, assuring them that if it threatened to harm them in the general election, they could run negative ads about Mr. Trump to create space between him and the Republican senators seeking reelection.

Of Mr. Trump, Mr. McConnell has said, "We'll drop him like a hot rock," according to his colleagues.

Is that what you told your colleagues?

MCCONNELL: Well, look, I can quote myself. I don't know what others have said about conversations that we've had.

But let me make the point that we've got a number of incumbent Republican senators running in very competitive states. Each one of those senators has done a terrific job and will be appealing to the people in their states based on their own performance. And that's what I think is the key to holding the Senate, is New Hampshire and Pennsylvania and Ohio and Wisconsin and Nevada and Colorado and Florida and Illinois for our candidates to be able to appeal based on their own records and their own views to the voters who will be participating this fall.

STEPHANOPOULOS: Is Donald Trump helpful or harmful to that cause?

MCCONNELL: Look, we're going to be running these Senate races no matter who the nominee is. We're not sure who the nominee is going to be yet. Look, we've got great candidates and I think we have an excellent chance to hold the Senate majority.

STEPHANOPOULOS: Senator McConnell, thanks for joining us this morning.

MCCONNELL: Thank you, George.

STEPHANOPOULOS: And let's get more on Judge Garland's nomination now from Dahlia Lithwick, senior editor and Supreme Court correspondent for "Slate" and Carrie Severino, chief counsel and policy director of the Judicial Crisis Network.

So we've got both sides staked out there, Dahlia. It doesn’t appear right now that Judge Garland is going to get a hearing. But let's talk about him on the merits.

Would he be a solid fifth vote on the liberal side?

And what kind of role would you expect him to play?

DAHLIA LITHWICK, SENIOR EDITOR AND SUPREME COURT CORRESPONDENT, "SLATE": I think that the consensus seems to be, George, that this is a judge and judge, this is a pretty moderate liberal. I think that if you look at his record, he's got a 19-year record on the Court of Appeals. You're going to find that he is very, very apt to follow precedent. He's very apt to rule narrowly. He's on Guantanamo on one side and then the other on -- by campaign finance, for it, against it, always, always just very clearly sticking to the facts --

(CROSSTALK)

STEPHANOPOULOS: But likely a fifth vote with the liberal bloc.

LITHWICK: I think that more often than not you're going to see him vote with the liberals. But I think that the notion that he's a hippie, wild-eyed liberal is probably way out.

STEPHANOPOULOS: And, Carrie, back in 2010, when there was another vacancy, you said Judge Garland was about the best that Republicans, conservatives could hope for under President Obama.

CARRIE SEVERINO, CHIEF COUNSEL AND POLICY DIRECTOR, JUDICIAL CRISIS NETWORK: Well, they could have done worse. They could have appointed Eric Holder. But I think it's very clear that he does exactly what this president wanted him to do, to take the court from a 4-4-1 balance and move it to the very reliable fifth vote.

If you don't believe me, ask "The New York Times." They said he would probably vote a little to the left of Justice Kagan and solidly with this bloc of five liberals. He has a gun vote that makes us think he doesn’t even think you have a Second Amendment right to have a gun in your own house for your own protection.

He defers to administrative agencies across the board. So the EPA doing its unconstitutional power grabs, trying to rewrite the laws, I think, absolutely would be in his camp.

Like I say, there's a real question he would probably be the fifth vote on abortion to get rid of limitations on abortion. That's why Planned Parenthood is supporting him --

(CROSSTALK)

STEPHANOPOULOS: What would be the case for anybody President Obama appointed -- ?

SEVERINO: Absolutely. But I think it clearly makes the court a solid liberal court as "The New York Times" said, probably the most liberal court we've had in the last 50 years.

STEPHANOPOULOS: Let me ask you, you know, some liberal groups a little bit disappointed by the pick of Judge Garland, 63 years old, white, moderate, they say --

(CROSSTALK)

UNIDENTIFIED FEMALE: Harvard.

STEPHANOPOULOS: -- Harvard, right, (INAUDIBLE) Harvard.

If Hillary Clinton is the Democratic nominee -- and she wins -- would Garland be the best first pick?

LITHWICK: I think that they will stick with Garland. I think that Obama was trying really hard, George, to change the subject from politics to the court. And I think Hillary's going to want to do the same thing.

I think that the idea here is let's talk about the Supreme Court; this is not about tantrums on the Right. This is not about, you know, issues on the Left. This is putting the best possible judge on the court --

STEPHANOPOULOS: The reverse question for you right now, then, as Jeff Flake said, if Hillary Clinton is the Democratic nominee and she wins, it would be better to approve Judge Garland in a lame duck session than gamble on her choice.

Do you agree with that?

LITHWICK: I think he's probably going to be as liberal as someone she's going to pick, frankly. But he may be, you know, 10 or even 20 years older than her ideal candidate.

You know, I think that the big principle here, as Senator McConnell said earlier, is the American people deserve a voice right now in this. They elected a Republican Senate to put a check on this -- on this president's expansive overreach and they're doing that right now.

After November, I think it's anyone's guess what's going to happen.

STEPHANOPOULOS: We're just about out of time.

Democrats aren't going to be able to break Senator McConnell, are they?

LITHWICK: Well, I think we're seeing little cracks, but I think that this looks like a tantrum that's going to go on for a long time.

STEPHANOPOULOS: Dahlia Lithwick, Carrie Severino, thanks very much.

And we'll be right back with David Muir live with the president in Cuba.

(COMMERCIAL BREAK)

STEPHANOPOULOS: And we're back now with President Obama about to make history today when he becomes the first American president to visit Cuba in more than 80 years.

"World News" anchor David Muir is on the scene in Havana.

We'll have an exclusive interview with the president -- David, what's the mood there in Havana today?

What kind of reception can the president expect?

DAVID MUIR, ABC NEWS CORRESPONDENT: I think there's going to be an extraordinary reception here, George. I have to tell you, though, Cubans are -- they want to hold onto their culture, their heritage, but they also want to embrace this opportunity, perhaps, for new economic freedoms.

As you mentioned, the president arrives here about 4:00 today, a little after, with the first family. He'll go to the embassy that's now been reopened.

He'll then tour Old Havana with the first family before spending some time with us and sitting down with us tomorrow.

As you know, George, a little more than a year ago, I asked the president, will you visit Cuba before the end of your second term?

And he said, well, let's look and -- and see how things evolve.

The president and the White House very aware that they're going to be asked, while he's on this trip, how has it evolved?

Has there been enough change when it comes to liberties here and -- and human rights?

He's aware of the criticism back home that this embargo still exists. He's found as many ways around it as he can, but we'll ask him, does he believe that he could do anything more?

And will this embargo be lifted, is there any chance during the end of his presidency?

He does not believe that's the case, thinks it will be the next president.

But I can tell you, here in Havana, George, where families make about $20 a month, fewer than 5 percent have Internet in their homes, they are prepared. But it's hard to predict how sweeping this change will be, if the people of Cuba are even ready for it.

STEPHANOPOULOS: It certainly is.

David Muir, thanks very much.

We're going to cover the president's historic trip.

Special coverage of the official welcome tomorrow. And, of course, that interview with David tomorrow on "World News."

And we're back after this from our ABC stations.

(COMMERCIAL BREAK)

STEPHANOPOULOS: That is all for us today.

Thanks for sharing part of your Sunday with us.

Check out "World News Tonight" and I'll see you tomorrow on "GMA."