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

NOTABLES:

• HOOSIER HORSE RACE: Today could spell the end of an era for a 35-year veteran of the Senate: Indiana's Dick Lugar. The long-time lawmaker is facing a tough race in his Republican primary against state Treasurer Richard Mourdock and the contest has implications far beyond the Hoosier State.

• VOTERS VOTING: In Wisconsin, Democrats will pick a recall challenger for Gov. Scott Walker. Recent polls show Milwaukee Mayor Tom Barrett with a lead over his top challenger.

• NOTE IT! In our virtual political roundtable, ABC's Rick Klein notes why the president's "evolving" position on gay marriage "defies credulity as well as political practicality" and Amy Walter on the good news/bad news about George Soros' big check to Democratic groups.

 

THE NOTE:

Voters in Indiana head to the polls today to pick a candidate in what has been one of the most interesting Senate primaries in recent memory.

Republican Sen. Dick Lugar is facing state Treasurer Richard Mourdock, who looks well positioned to unseat the long-time incumbent. It's a race that has drawn considerable attention and money.

As ABC's Chris Good points out, "Lugar has spent $6.7 million to Mourdock's $2 million defending himself, with Mourdock's PAC and super PAC backers ($2.9 million) outspending Lugar's ($1.7 million)." http://abcn.ws/KHubkW

A loss by Lugar, who first came to the Senate in 1977, would represent the end of an era. He was a conservative, but one who was willing to reach across the aisle.

His demise would tell us a few things:

-Being a 35-year incumbent who doesn't own a home in the state you represent is bad . This became a huge issue in Mourdock's campaign against Lugar.

-This outcome wasn't inevitable. After all, the writing was on the wall for two years that he'd be targeted. But, Lugar chose not to - or just plain couldn't - run a disciplined campaign. This from Evansville Courier columnist Eric Bradner: "Despite seeing a challenge coming, it never built a publicly-visible component like a bus tour or rally to accompany its phone banks and commercials, and it never engaged and organized the constituencies that Lugar has helped over the years to the extent it needed to. The biggest problem, though, is the lack of the kind of a coherent message that would really let Hoosiers know what they'll lose if Lugar is gone - an antidote to the anti-incumbent mood in the one-on-one race he finds himself in." http://bit.ly/J9RPGD

-Mourdock may not call himself the Tea Party candidate, but he sure as heck sounds like one. And, he's likely to act like one if he gets to Washington in 2013.

-Democrats say they have good chance to pick up this seat. Polls show a Joe Donnelly-Mourdock race tied. But, that reflects more on the fact that both candidates are relatively unknown. Also, it'll be interesting to see if Democrats put their money where their mouth is. In a year when Democrats are forced to defend at least eight of their own seats, a pick-up in a red state like Indiana seems like a luxury they may not be able to afford.

More from ABC's Chris Good about what the outcome of today's Indiana Senate primary means and what it doesn't: http://abcn.ws/KHubkW

NOTE IT!

ABC's AMY WALTER. Today's New York Times story about billionaire George Soros' plan to pump money into the coffers of some liberal groups is good news for super PACs like American Bridge who want to build up an infrastructure for the long haul. But pushing money for organizing and turn-out means red state candidates get left out in the cold.

ABC's RICK KLEIN: Evolution, of course, takes time. But President Obama doesn't have as much time as some campaign aides may like when it comes to clarifying his position on gay marriage. Vice President Joe Biden and now two of the president's Cabinet secretaries are forcing the questions to be asked now, and they'll grow through the summer, when Democratic activists seek a gay-marriage plank in the party platform. Votes like today's in North Carolina may make the president's incomplete answer look like smart politics. But the concept that the president's position on gay marriage is officially "evolving" all the way through the election defies credulity - as well as political practicality.

GAY DONORS BOYCOTTING OBAMA? The Plum Line's Greg Sargent reports: "Some leading gay and progressive donors are so angry over President Obama's refusal to sign an executive order barring same sex discrimination by federal contractors that they are refusing to give any more money to the pro-Obama super PAC, a top gay fundraiser's office tells me. In some cases, I'm told, big donations are being withheld." http://wapo.st/IDiNWC

NC VOTING ON SAME-SEX MARRIAGE TODAY. North Carolina will vote on a same-sex marriage ban today, and ABC's Elizabeth Hartfield reports on what the ballot measure would do: "The constitutional amendment will bar same sex marriage, but it also goes much further in that it bars civil unions," says Jean Cary, Professor of Law at Campbell Law School in Raleigh, N.C. Several counties and towns within the state offer domestic partnership benefits to both gay and straight couples. But those benefits would be in jeopardy if the bill passes. http://abcn.ws/Jt2oW1

NOTED: In March, more than 50 percent of Americans backed gay marriage for the first time in ABC News polling. http://abcn.ws/Jd7KEe

CHANGING ATTITUDES. From Gallup's remarkable long-term trends: In 1988, 57 percent said "gay or lesbian relations between consenting adults" should be illegal. In 2011, it dropped to 33 percent. http://bit.ly/IFbVYV

NARROWING RACIAL DIVIDE ON GAY MARRIAGE. Pew Research Center reported in April: "In 2008, there were sizable differences in opinions about gay marriage among whites and blacks. While whites opposed gay marriage by a modest 51% to 41% margin, blacks opposed gay marriage by more than two-to-one (63% to 26%). But the gap has narrowed. Since 2008, the proportion of African Americans favoring gay marriage has increased from 26% to 39%, while opposition has fallen from 63% to 49%." http://bit.ly/IKadHp

 

YOUR VOICE, YOUR VOTE: MEET VIRGINIA. President Obama and Mitt Romney kicked off their campaigns in the critical battleground state of Virginia last week, and in interviews with voters who live everywhere from Arlington to Hampton Roads, these Virginians agree on thing: it's going to be a tight race in the Old Dominion this fall. President Obama's most vocal supporters, some of whom attended his rally on Saturday evening in at Virginia Commonwealth University in Richmond, said he has not gotten enough credit for the accomplishments of his first term.

"I think it's been a very tough scenario both on the economic front, on the international front and definitely on the Congressional front. To have the kind of Congress he's dealing with is very challenging," said Jaime Areizaga, a lawyer from Arlington. "I will do as much if not more than in 2008 because for me the contrast is clear. Has it been a perfect presidency? No. but the alternative is so much worse."

"I think he's done a very good job. I think he's saved the country from another Great Depression, which he doesn't get enough credit for," Florence Buchholz of Charlottesville told ABC News. "These are problems that took a long time to reach this state and it's going to take a while, but things are headed in the right direction."

Although Republicans are still warming up to their newly-minted GOP nominee, Mitt Romney, voters say they are most enthusiastic about making Obama a one-term president.

"I'm excited about anybody but Barack Obama," said Daniel Jones, a maintenance mechanic in Portsmouth, Va. "This is an important election, I don't want to be Greece, and that's where we're going."

"I'm satisfied with Romney," Dan McDonald of Carrollton, Va. told ABC News. "He's going to get my vote no matter what come November 6 because I don't want to stay on the same path that we're currently on."

And Jim Hewitt, an elected school board member in Portsmouth said of Romney: "He's a turnaround specialist and that's what our country needs, so I'm excited."

FROM THE DESK OF THE OBAMA CAMPAIGN: "Today, Obama for America National Press Secretary Ben LaBolt and Michigan Democratic Party Chair Mark Brewer will hold a call in advance of Mitt Romney's speech in Lansing, MI - highlighting Romney's record of making it harder for middle class families to send their children to college. Romney will be speaking at Lansing Community College, a choice of venue at odds with his comments on Monday describing student loans as 'free stuff.'"

Romney, yesterday, in Ohio: "You're going to hear that, in an effort and try and reengage college students and graduate students to get involved in the Obama campaign - and they're pulling back, obviously, they're not as enthusiastic as they were - in an effort to try and get them engaged, he's going to promise giving a lot of free stuff to them and say, I'll pay for your education or I'll pay for the loans."

 

BOEHNER WARNS OF IRANIAN INFLUENCE. House Speaker John Boehner will deliver a speech on Latin America this morning at the Washington Conference on the Americas, where he will warn of Iran's influence in the hemisphere. Excerpt: "The same week our delegation was visiting Brazil, Colombia, and Mexico, another foreign leader was conducting a Latin America mission as well. … Ahmadinejad was being hosted by nations such as Venezuela and Cuba, whose governments have been linked to state-sponsored terrorism and have isolated themselves internationally.  His trip underscored the designs Iran has for expanding its influence in Latin America, and its eagerness to forge bonds with governments in the Western Hemisphere that have demonstrated a lesser interest in freedom and democracy."

 

THE BUZZ

with ABC's Chris Good ( @c­_good)

WISCONSIN TO PICK WALKER'S CHALLENGER. ABC's Elizabeth Hartfield on Tuesday's recall primary: Recent polls showed Milwaukee Mayor Tom Barrett with a strong lead over former Dane County Executive Kathleen Falk. Polls also showed Barrett, who ran against Walker for governor in 2010, in a dead heat with Walker. Falk trails Walker in the polls. http://abcn.ws/IF19lu

VEEPSTAKES: WHAT ABOUT THE DONALD? So far Donald Trump's name hasn't been in the mix as one of Mitt Romney's potential vice presidential picks, but could he be a contender? The real estate mogul and reality television star endorsed Romney relatively early - back in early February - and since then he's been a tireless campaigner for the former Massachusetts governor, holding high-dollar fundraisers (including a recent birthday party in New York City for Ann Romney), pitching in with radio interviews, and recording robo-calls in primary states. "At the present time, Mr. Trump is committed to assisting Mitt Romney and ensuring that Barack Obama becomes a one term president," said Michael Cohen, special counsel at the Trump organization. "In the future, if the opportunity presents itself where Mr. Trump is offered the position of vice president, I suspect he would seriously consider it." What would Trump bring to the ticket? Those close to him cite business experience, charisma, his fundraising rolodex and even his own personal wealth. Cohen, in an interview with ABC News, also indicated Team Trump is as ready as ever to take on an attack dog role: "Irrespective of how much money Obama raises and how vicious the attacks against Mitt will be this time," he said, "President Obama is running on his record, which irrefutably is a failure."

WOMAN ALLEGES OBAMA TREASON, ROMNEY STALLS. ABC's Emily Friedman: Instead of addressing the "treason" reference by the woman, who went on to ask what the candidate would do to balance the three branches of government and restore the Constitution, Romney responded, "As I'm sure you do, I happen to believe that the Constitution was not just brilliant, but probably inspired. I believe the same thing about the Declaration of Independence." http://abcn.ws/K796Vs

SANTORUM ENDORSES ROMNEY. ABC's Shushannah Walshe: Rick Santorum has officially endorsed Mitt Romney, and notified his supporters in an email sent Monday night. In the email, the former presidential candidate cited his Friday meeting with Romney in his hometown of Pittsburgh as a reason he finally got behind the presumptive GOP nominee. … He ended the letter promising his supporter he will have details of his own new venture soon. http://abcn.ws/JaA9g2

LABOR GETS BEHIND OBAMA, AFTER ALL. Politico's Joseph Williams reports that rumblings to the contrary were empty threats: "The Teamsters' Monday endorsement makes it the latest major union to fall in line behind the president's campaign … it also underscores a broader political point: after three years of ups, downs and mutual frustrations, Big Labor is again marshaling its troops for Obama with a mood that could be described in some quarters as grudging enthusiasm." http://politi.co/J9YL8O

DCCC DELIVERS 'SCANDAL CALENDAR.' ROll Call's Jonathan Strong on the latest PR stunt: "Operatives from the Democratic Congressional Campaign Committee hand-delivered a 'scandal' calendar to every GOP lawmaker Monday … with January graced by Rep. Vern Buchanan (Fla.), the finance chairman of the National Republican Congressional Committee who is under investigation for possible campaign finance improprieties." http://bit.ly/IGRjEF

DEM DONORS GO FOR THE GRASSROOTS. The New York Times' Nick Confessore: "After months on the sidelines, major liberal donors including the financier George Soros are preparing to inject up to $100 million into independent groups to aid Democrats' chances this fall … the donors are focusing on grass-roots organizing, voter registration and Democratic turnout. … Mr. Soros will contribute $1 million each to America Votes … and American Bridge 21st Century, a super PAC that focuses on election-oriented research." http://nyti.ms/KBn8Qv

ROMNEY CAMPAIGN FACEBOOK. In our ongoing feature chronicling the members of Team Romney, today we add Spencer Zwick, the candidate's 32-year-old finance director: He is so close to the Romney clan that he's like a member of the family, and he's known as the sixth son for those Romney-like good looks. http://abcn.ws/L07OM8

TWITTER FIGHT! MCCAIN VS. BARKLEY. ABC's Elizabeth Hartfield on the #shotsfired: @SenJohnMcCain tweeted, "Dear Charles Barkley, 'don't take it personally, you seem like a nice guy,' but you're clueless - @MittRomney wins. Wanna bet?" http://abcn.ws/IEhua2

BEST QUIRKY AD OF THE CAMPAIGN CYCLE SO FAR? ABC's Amy Walter spots an ad for Roland Sledge, who is running for a seat on the Texas Railroad Commission. It involves a guy peeing on an electric fence. Seriously.   WATCH: http://bit.ly/IErdD7

 

WHO'S TWEETING?

@HowardKurtz: Santorum endorses Romney by email? Isn't that one notch above breaking up with someone by text message?

@pbsgwen: Honest question. When is the last time we've seen a series of such delayed, grudging endorsements?

@dickstevenson: Hillary Clinton to   @markleibovich  on Biden's role: "Being a vice president is kind of like being a first lady."   http://nyti.ms/IF4YqT

@HotlineAlberta: 2016 watch: NY Gov. Andrew Cuomo to write autobiography, will be published in 2014 -   http://www.buffalonews.com/city/capital-connection/albany/article846100.ece

 @mollyesque: Just hanging out on the beach at a Steny Hoyer fundraiser in Puerto Rico and…what's that in the water?! http://www.politico.com/news/stories/0512/76013.html

 

POLITICAL RADAR

-Mitt Romney campaigns at Lansing Community College in Lansing, Michigan.

-President Obama will speak about the economy at the College of Nanoscale Science and Engineering's Albany NanoTech Complex at the State University of New York in Albany.

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