By MICHAEL FALCONE ( @michaelpfalcone ) and AMY WALTER ( @amyewalter )

NOTABLES:

• EXCLUSIVE:  ABC's Robin Roberts sits down with President Obama today at the White House for an exclusive interview. Watch it tomorrow on "Good Morning America."

• END OF AN ERA: What the defeat of a 36-year veteran of the U.S. Senate means for bipartisanship, what it signals about the November presidential election and what it means for Democratic hopes of picking up the Indiana seat.

• LUGAR'S LAMENT: Richard Lugar on Richard Mourdock: "What he has promised in this campaign is reflexive votes for a rejectionist orthodoxy and rigid opposition to the actions and proposals of the other party. … This is not conducive to problem solving and governance."

• NOTE IT! ABC's Rick Klein on why Lugar's defeat means it's time to retire the Senate's moniker as the "most exclusive club" and Amy Walter on how this week's gay marriage flap may not be as much of a problem for the Obama Administration as some thnink.

THE NOTE:

Indiana's state treasurer had a simple explanation last night for how he was able to defeat fellow Republican, Richard Lugar, a more than three-decade veteran of the Senate.

"Hoosiers," Richard Mourdock said in his victory speech, "want to see Republicans inside the U.S. Senate take a more conservative track."

And with that, Mourdock, with the help of an infusion of cash and support from conservative and Tea Party groups, felled one of the Senate's last remaining moderates - a long-time lawmaker with a history of reaching across party lines.

"We are experiencing deep political divisions in our society right now," Lugar, who has served in the Senate since 1977, said in a statement following the results of last night's primary. "These divisions have stalemated progress in critical areas."

And former Indiana Democratic senator Evan Bayh told ABC News's Chris Good in a recent interview, "In some ways what's going on in Indiana is a microcosm of what's going on nationally in the Republican Party."   http://abcn.ws/JdBylR

As The New York Times' Monica Davey points out, Lugar's defeat "seemed to serve as a caution to moderates on both sides of the aisle. In February, Senator Olympia J. Snowe of Maine, a moderate Republican, decided not to run for re-election, citing polarization in Washington. Senators Kent Conrad of North Dakota, a Democratic fiscal centrist, and Jim Webb of Virginia, a moderate Democrat, are retiring. Two other moderate Democrats, Senators Claire McCaskill of Missouri and Jon Tester of Montana, face tough re-election races." http://nyti.ms/JcEAa1

The Associated Press' Thomas Beaumont wrote that yesterday's loss by Lugar, which had become something of a foregone conclusion, signaled that "anti-incumbent sentiment is coursing through the electorate, a potentially ominous sign for the incumbent Democratic president seeking a second term and lawmakers of all political stripes."   http://apne.ws/JcITpw

But as Beaumont pointed out, there's a rub for Republicans too: "The GOP also remains deeply split between the establishment wing and insurgent tea party, a fissure that underscores the challenge the presumptive Republican presidential nominee and other GOP candidates face in the months ahead to unite the party."

There's a running debate about whether Lugar's loss can labeled a Tea Party win. After all, Murdouck is a sitting statewide official, not a Christine O'Donnell-type gad fly. Lugar's age, his lack of residency in the state and his 35 year tenure in DC - more than ideology - were the bigger reasons for his loss.

That said, it's worth noting that "survivors" of GOP primary challenges like Arizona's John McCain and, very likely, Utah's Orrin Hatch, are also long-time creatures of the Senate who have at times (gasp) worked across the aisle

They won, in part, by disavowing their past ways (remember "build that dang fence"). In that way, then, the Tea Party won too. Their agenda is no longer considered fringe but now fully embraced by GOP establishment.

LUGAR GETS THE LAST WORD.  From a statement the outgoing Indiana senator circulated this morning: "If Mr. Mourdock is elected, I want him to be a good Senator. But that will require him to revise his stated goal of bringing more partisanship to Washington. He and I share many positions, but his embrace of an unrelenting partisan mindset is irreconcilable with my philosophy of governance and my experience of what brings results for Hoosiers in the Senate. In effect, what he has promised in this campaign is reflexive votes for a rejectionist orthodoxy and rigid opposition to the actions and proposals of the other party. His answer to the inevitable roadblocks he will encounter in Congress is merely to campaign for more Republicans who embrace the same partisan outlook. He has pledged his support to groups whose prime mission is to cleanse the Republican party of those who stray from orthodoxy as they see it. This is not conducive to problem solving and governance. And he will find that unless he modifies his approach, he will achieve little as a legislator. Worse, he will help delay solutions that are totally beyond the capacity of partisan majorities to achieve."

THE VIEW FROM INDIANA. Indianapolis Star political columnist Matthew Tully penned these thoughts on the outcome of the Mourdock-Lugar primary: "For some of us, it's hard to look at the dysfunction of recent years in on Capitol Hill and not think that we need more lawmakers like Lugar - those who in previous political climates were praised for their bipartisanship and cooperative pragmatic styles, and for their ability to take on vital if unglamorous global issues. But times have changed, and many Republican primary voters - driven in many cases, it should be said, by deep concerns about the nation's condition - seem intent on nominating more uncompromising candidates such as Tuesday's winner: state Treasurer Richard Mourdock, a nice enough man but also one who proudly declared recently that the problem in Washington 'is too much bipartisanship.'" http://indy.st/IPinjG

WHY LUGAR'S LOSS COULD BE A WIN FOR DEMOCRATS. ABC's Chris Good reports that Dick Lugar's loss is welcome news for Democrats, who seem to have figured all along that their candidate, Blue Dog Rep. Joe Donnelly, would fare better against Tea Party-backed, Saran Palin-endorsed state Treasurer Richard Mourdock in November. Democrats have held back opposition research on Mourdock in the hope that he would win the primary. Now that he has, we can expect a barrage of stored-up attacks. "This dude is Ken Buck," one Democratic operative said, in reference to the failed Republican Senate in Colorado in 2010.   http://abcn.ws/JTUmDJ

The Democratic Senatorial Campaign Committee released a memo this morning from Executive Director Guy Cecil outlining some (or maybe all) of what's in store. Cecil wrote:

-Mourdock spent $2 million of taxpayer money on a lawsuit that could have endangered 124,000 Indiana jobs, including 4,000 high-paying jobs in Kokomo, Indi., by killing Chrysler's bankruptcy restructuring. Mourdock called the lawsuit his "Rosa Parks moment." Mourdock's Tea Party opposition to the entire auto industry rescue could have cost the state 140,000 jobs in total.

-In his defense, Mourdock says, "I didn't take a pledge that I would support every job in Indiana under whatever means it takes to do it."

-Mourdock says that "I think there needs to be more partisanship" in Washington.

-Mourdock has questioned the constitutionality of Social Security and Medicare.

EXCLUSIVE: ROBIN ROBERTS INTERVIEWS PRESIDENT OBAMA. "Good Morning America" anchor Robin Roberts will sit down with President Obama today. The interview will air tomorrow on "Good Morning America" and other ABC broadcasts. See the whole picture, from inside the White House… Tune in: http://bit.ly/J6rN9T

 

NOTE IT!

ABC's RICK KLEIN: Sen. Richard Lugar's crushing primary defeat means it's time to retire the description of the Senate as the "most exclusive club." The forced end to a six-termer's career, at the hands of a challenger who ran against the Senate as much as he did Lugar himself, shatters the idea of exclusivity of an institution only for men and women who think and live a certain way. And the quiet and not-so-quiet urging Richard Mourdock got from sitting senators, plus Mourdock's early noises about not particularly caring for GOP leadership, are reminders that the "club" part of the Senate no longer applies, either.

ABC's AMY WALTER: Jay Carney may be getting pummeled by the press every day on the administration's "evolving" views on gay marriage, but talk to gay activists and they don't see much there, there. In fact, the gay community has been rather nonplussed by the whole thing, with a number of activists telling me that they see Biden's comments as just "Joe being Joe." Moreover, they don't have much desire to push the President to embracing marriage before November.

VIDEO OF THE DAY: Will gay marriage haunt Obama in November? Obama, White House continue to twist themselves into pretzels over gay marriage. http://yhoo.it/IHXNhu

 

ROMNEY: CLINCHING THE DELEGATES…ALMOST. ABC's Elizabeth Hartfield on Mitt Romney's three primary wins:  With a total of 132 delegates at stake, Romney will not reach the 1,144 on Tuesday. The earliest that can happen is by Texas's primary, which will take place on May 29. http://abcn.ws/Jcktw6

THE BUZZ

with ABC's Chris Good ( @c­_good)

WALKER GETS A CHALLENGER. ABC's Elizabeth Hartfield on Wisconsin Democrats' recall primary: Milwaukee Mayor Tom Barrett won the Democratic primary in Wisconsin on Tuesday … polls had showed him with a large lead over former Dane county executive Kathleen Falk, who was viewed as his biggest competitor and had been endorsed by many of the labor organizations in the state. http://abcn.ws/L5MulU

A Note from the Republican Governors Association on the primary results: "Governor Walker finished with more votes than the combined vote totals of Tom Barrett and Kathleen Falk, and just 8 percent fewer votes than were cast altogether in the Democratic primary."

ON THE AIR: NEW AD VS. WALKER (VIDEO). The Progressive Change Campaign Committee says it's spending $30,000 to air this Wisconsin recall ad on The Colbert Report and Sunday shows and is raising more money to expand the buy. http://youtu.be/tF7p1CZ1q3M

NOTED: OBAMA'S CHALLENGER: INMATE NO. 11593-051. ABC's Elizabeth Hartfield on the Democratic primary vote in West Virginia: Keith Judd, who is serving out a 17.5 year sentence for extortion, currently has received 40 percent of the vote, with 83 percent of precincts reporting, according to The Associated Press. Obama currently has received 60 percent of the vote. http://abcn.ws/K0XCPy

VIDEO: SCOTT BROWN'S FIRST TV AD. The Massachusetts senator will begin airing his first campaign ad on Thursday, highlighting his independence from the Republican Party. http://youtu.be/euix3FKxGNc

MICHELE BACHMANN IS A 'SWISS MISS' Politico's Tim Mak: "Bachmann (R-Minn.) recently became a citizen of Switzerland, making her eligible to run for office in the tiny European nation, according to a Swiss TV report Tuesday. … the former Republican presidential candidate became a citizen March 19." http://politi.co/IOF5IL

HILLARY CLINTON DOESN'T CARE HOW SHE LOOKS. ABC's Dana Hughes on Clinton's response to a Drudge headline and photo of her sans makeup: "I feel so relieved to be at the stage I'm at in my life right now, Jill, because if I want to wear my glasses, I'm wearing my glasses," said Clinton [to CNN's Jill Doherty]. "If I want to pull my hair back, I'm pulling my hair back." http://abcn.ws/IXs2Hp

VIDEO: MARK KIRK'S STROKE REHAB. The Los Angeles Times' Katherine Skiba posts video of the Illinois senator, who suffered a stroke in Janyary. "They have some devious ways of making things more difficult on you," Kirk says of his rehab process. The video shows him training to walk on a treadmill. http://lat.ms/IYu8Ab

RUBIO STILL PAYING OFF STUDENT LOANS. Obama isn't the only one whose student debt dogged him, ABC's Arlette Saenz reports: "I think I am one of the only senators here who still has a student loan," Rubio said in a paper statement. "As someone with a student loan and with a state with so many people with student loans, I support a hundred percent making sure that the interest rates on student loans do not go up." http://abcn.ws/JcwJJR

MORE SPANISH ADS FROM OBAMA. ABC's Mary Bruce reports: The ads, which will air in Colorado, Nevada and Florida, tout the president's record on healthcare as it relates to the Hispanic community, a key Democratic voting bloc. http://abcn.ws/LHuZv4

OBAMA, KERRY, WARNER LAMENT LUGAR LOSS. All three issued statements Tuesday night praising Sen. Dick Lugar. Kerry: "This is a tragedy for the Senate and the loss is particularly felt by all of us who have been privileged to serve with Dick on the Foreign Relations Committee." Obama, who featured Lugar in a 2008 campaign ad: "While Dick and I didn't always agree on everything, I found during my time in the Senate that he was often willing to reach across the aisle and get things done." Former Virginia GOP senator John Warner, who served for 30 years until 2009: "Regardless of the outcome tonight, through his years of tireless work, Senator Lugar will be remembered as a Giant in the Senate." http://abcn.ws/IORwEx

NOTED: MAYBE NOT LUGAR'S WORST DAY. Politico's Charles Mahtesian: "It was on April 19, 1995, the day of the Oklahoma City bombing, that he declared his presidential candidacy in Indianapolis." http://politi.co/KL1SSU

EDWARDS DONOR WARNED OBAMA: DON'T PICK HIM. MSNBC's M. Alex Johnson on testimony in the Edwards trial: "The donor, Tim Toben, a prominent developer in Chapel Hill, N.C., said he called the Obama campaign in June 2008 after Edwards told him that he might be Obama's running mate. Toben said he warned Obama advisers because he feared that Edwards' affair would have "destroyed" Democratic chances in the general election." http://on.msnbc.com/IGbeyr

HOW EDWARDS DECIDED TO COME CLEAN. The New York Times' Kim Severson on testimony from his longtime speechwriter, Wendy Button: "First and foremost, she said, Mr. Edwards wanted to make a public declaration to Frances Quinn Hunter, the girl he fathered with the campaign videographer Rielle Hunter … Ms. Button said she continued over a series of days to coax Mr. Edwards to be completely honest." http://nyti.ms/JbIkMC

MEET VIRGINIA. ABC's Michael Falcone on the tight presidential race unfolding there: Interviews with politically-engaged Virginians who live everywhere from Arlington to Hampton Roads, revealed an electorate that is beginning to tune into an unfolding 2012 election drama in which their state is front and center. … Virginia GOP Victory Chairman Pete Snyder said that 9 "victory centers" were already open across the Commonwealth. "The most ever open this early in Virginia," Snyder noted. http://abcn.ws/JoXE6y

WHY SANTORUM WAITED TO ENDORSE. ABC's Shushannah Walshe on Santorum's explanation to Jay Leno: "I think we just needed some time," Santorum told Leno. "It was a rough-and-tumble campaign. I can't say it would have been an easy thing the next day to turn around and say, 'Let's just go forward.' http://abcn.ws/KOCWcz

ROMNEY MOCKS OBAMA'S 'JULIA' CAMPAIGN. The Los Angeles Times' Maeve Reston: "'This little cartoon that they have on the life of Julia really reveals the weakness of the president's policies,' the presumed Republican nominee told Fox News host Sean Hannity during a taped interview that aired Tuesday night. 'To have to defend your record by coming up with a cartoon character, as opposed to real people, suggests that he doesn't want to talk about his record at all.'" http://lat.ms/LMCH7d

SECRET SERVICE SCANDAL: WHAT WENT WRONG? Plenty, according to Senate Armed Services Chairman Carl Levin, D-Mich., ABC's Sunlen Miller reports: "The investigation has found gaps, some significant gaps, that existed in a number of ways," Sen. Carl Levin said … failure to notify the chain of command of the assignment of certain personnel in their chain of command to Colombia … failure to notify the chain of command promptly of the events that took place in Colombia, including the decision to keep suspected people there …the decision to keep those suspected personnel on the mission was made without the input of the higher-ups on the chain of command. http://abcn.ws/IGKVrU

WHO'S TWEETING?

@jmsummers : AP: Support for the war in Afghanistan has reached a new low, with only 27% of Americans saying they back the effort. http://huff.to/IPL689

@onmessageinc : Primary results NC, IN, and coal-WV show it's not 2008 anymore. #POTUS2012 will be won in WI, FL, OH, CO, NV, PA. Pull up a chair.

@ZekeJMiller : Restore Our Future: "Happy Mother's Day From Barack Obama's Team" re: Maher, Hilary Rosen attacks on  @anndromney http://www.buzzfeed.com/zekejmiller/romney-super-pac-defends-ann-romney-from-rosen-ma

@jwpetersNYT : Inside Obama's ad shop, a seasoned political warrior. What Jim Margolis' campaign history hints about Obama 2012: http://nyti.ms/KDzw2m

  @maggiepolitico : Campaigning, living in their state MT@jonward11 grt  @mkraju piece on R senators up in 2014 r trying 2 avoid lugar fate  http://bit.ly/IKzswt

 

POLITICAL RADAR

-Mitt Romney brings his message to Colorado with a morning campaign event in Fort Lupton, located outside Denver. Then, Romney travels to Oklahoma City, appearing with the state's Governor at Republican Party Headquarters.

ABC's Josh Haskell (@HaskellBuzz)

 Check out The Note's Futures Calendar:  http://abcn.ws/ZI9gV