The Note: Keeping An Eye On The Court

— -- NOTABLES

--MEET THE MAN BEHIND THE SUPREME COURT SAME-SEX MARRIAGE CASE: Jim Obergefell's case will affect the marriage laws under which about 200 million Americans live, but the reason he sued his home state of Ohio was very personal: To make state bureaucracy recognize him as the widower of his late partner of 21 years, John Arthur. They were legally married in Maryland just a few months before John died in 2013 -- but in 2004, Ohio voters had amended their state constitution to prohibit gay marriage from being "valid in or recognized by" the Buckeye State. Today, Obergefell's lawyer will argue his case before the Supreme Court. Obergefell sat down with ABC's ADAM TEICHOLZ to tell the story of his long relationship, short marriage, and how he went from grieving partner to unlikely activist. http://abcn.ws/1JNwiDr

--ANALYSIS -- ABC's RICK KLEIN: The script may be flipped, but that doesn't mean the story is over. The Supreme Court could go as far as to establish a constitutional right for same-sex couples to marry as a result of the cases being argued on Tuesday. That would change the terms of the debate for 2016, surely. But the scope of that debate is likely to be determined by emphasis inside the Republican field, not by a diversity of policy positions. Perhaps remarkably, an extremely crowded GOP debate field is not likely to include any supporters of gay marriage, despite fast-moving public opinion on a position that has support above 60 percent in the latest ABC News/Washington Post poll. That means the debate is likely to be colored by candidates who will simply attack judicial activism, versus those who revive a push for a constitutional amendment to ban gay marriage. There's a call to awakening evangelicals and other devoutly religious voters in the messaging of candidates including Ted Cruz, Bobby Jindal, and Rick Santorum, just for starters. It's possible that gay marriage is essentially universal in the United States before next year's election. But just because Democrats feel like they're on offense doesn't mean at least some of the Republicans will stop calling plays.

--HAPPENING TODAY -- LABOR LAYS IT DOWN: AFL-CIO President Richard Trumka will deliver a speech on the 2016 race today, laying out what the group wants to see from presidential candidates. This is a chance for labor to set some markers for what it'll take to gain their support -- particularly for Hillary Clinton, as she vies against progressive candidates on her left flank in the Democratic primary, ABC's CHRIS GOOD reports. "As the presidential campaigns begin, workers have a very clear question: Will candidates be and think and act big enough to seize this historic opportunity?" Trumka will say, according to excerpts of his remarks as prepared for delivery. "Will they look past what Washington says can't be done and do what America needs? Will they overcome our skepticism? Will they present a vision that's authentic, bold and unequivocal? Will our candidates meet the moment?"

THE BUZZ

with ABC's VERONICA STRACQUALURSI

AMERICAN PRISONER IN IRAN TAUNTED AFTER OBAMA'S WHITE HOUSE CORRESPONDENTS' DINNER SPEECH. Just hours after President Obama used his appearance at the White House Correspondents' Dinner to call for the release of an American journalist held prisoner in Iran, another American held at the same prison was taunted by Iranian prison guards who told him the president did not mention his name, his family said. The prisoner, Marine Corps veteran Amir Hekmati, called his mother over the weekend from the notorious Evin prison in Tehran, terrified that gaining his release is not a priority for the U.S. government, his family said. Now, in an emotional letter to the White House, Amir's sister is demanding to know why the president has never said her brother's name in public. Of the three Americans known to be imprisoned in Iran, Hekmati has been held the longest, ABC's JONATHAN KARL and MARY BRUCE report. He was arrested in 2011 when, according to his family, he was visiting his ailing grandmother in Iran. http://abcn.ws/1EKxFF3

THE SCENE OUTSIDE THE COURT: PART TAILGATE, PART DEBATE STAGE The scene outside the Supreme Court Monday felt a lot like a football game tailgate party -- and for supporters and opponents of same-sex marriage who have spent days camped out to score a seat, today's oral arguments are the Super Bowl. The justices will hear arguments into two related questions: one, whether states must allow same-sex couples to marry; and two, whether states must recognize same-sex marriages performed elsewhere, according to ABC's ALI WEINBERG. There were at least sixty groups -- mainly supporters, but also some opponents -- who had been waiting on the corner of First and East Capitol Streets for days, hoping for a coveted chair inside the courtroom. http://abcn.ws/1KoSXH9

MARTIN O'MALLEY RESPONDS TO BALTIMORE PROTESTS. While the Baltimore protests and riots over the death of Freddie Gray were happening last night, former Maryland governor and Baltimore mayor Martin O'Malley decided to cut his trip to Europe short and fly back home, according to the Washington Post. O'Malley, who is considering a run for president in 2016, responded on social media last night to the events that unfurled in the city he previously served as mayor before winning the governorship. "I'm saddened that the city I love is in such pain this night. All of us share a profound feeling of grief for Freddie Gray and his family," O'Malley wrote in a Tweet. "We must come together as one city to transform this moment of loss and pain into a safer and more just future for all of Baltimore's people."

IN THE NOTE'S INBOX

--PRO-TRADE COALITION LAUNCHES SIX-FIGURE AD BUY.The Business Roundtable-led Trade Benefits America Coalition has made a six figure cable television advertising buy promoting passage of the Bipartisan Congressional Trade Priorities and Accountability Act of 2015, a source tells The Note: "Titled 'One Thing,' the ad reminds viewers that trade is a vital component of economic growth in the American economy, with trade promotion authority helping the U.S. craft stronger trade agreements that ultimately benefit American workers. The ads will begin airing on national cable and in targeted media markets across the country this week."https://youtu.be/FSG6D3LVAOA

--A CHANGE AT TYSON FOODS.A source e-mails The Note: "Tyson Foods, one of the largest food companies in the country, is announcing today the elimination of human antibiotics from their chicken production chain by 2017. Given that Tyson is the primary provider of chicken to McDonalds, this has some reverberations around the country. Additionally, they are announcing the formation of independent advisory councils that are looking at ways to eliminate the use of human antibiotics in all of their beef, pork and turkey supply chains to discuss ways to reduce the use of human antibiotics on cattle, hog and turkey farms."

IN CASE YOU MISSED IT>

CHECK OUT THE NEW OBAMA 'KAILUA BLUE' CHINA. The state dinner on Tuesday for Japanese Prime Minister Shinzo Abe will be a celebration of "a long-awaited spring and the long-awaited Obama china. Guests at the lavish dinner will be treated to toro tartare, Wagyu tenderloin and silken custard cake prepared by famed chef Masaharu Morimoto, all served on the newly unveiled 11-piece Obama state china. It took three and a half years and countless consultations to design the new service, which is manufactured by Pickard China of Antioch, Illinois, according to White House officials, ABC's MARY BRUCE notes. http://abcn.ws/1dlS4nC

WHO'S TWEETING?

@GMA: "I want you all to get justice for my son, but don't do it like this" says Freddie Gray's mom. @SteveOsunsami reports

@LarryHogan Late last night I visited injured #Baltimore police at @shocktrauma & thanked them for their service to our city.

@jonallendc: SCOOP: The 181 Clinton Foundation donors who lobbied Hillary's State Department. Get the list here. http://t.co/l1u25B2J0A

@ron_fournier: What the Clintons and many in the media don't get about the email and @ClintonFdn stories http://www.nationaljournal.com/2016-elections/the-proof-of-the-clintons-wrongdoing-20150427

@gerrymullany: Koch-funded group squares off against the Pope on climate change: http://t.co/3peOFaUOc8