But once Mr. Obama began laying out his administration's achievements on gay rights, an attendee interrupted and yelled out for him to address same-sex marriage. He paused and quipped that "believe it or not I anticipated" the question - and then added, "Where was I?"
It was just one of several instances in which attendees yelled out for Mr. Obama - who has been the most pro-gay rights president in U.S. history - to address the issue.
The fundraiser came as the New York state legislature appeared poised to pass same-sex marriage into law - a potentially historic moment since it would mark the first state legalizing same-sex marriage without going through the courts. The president notably declined to take a position on that vote, saying only that "Under the leadership of Governor Cuomo with the support of Democrats and Republicans, New York is doing exactly what democracies are supposed to do."
Mr. Obama has long said that he supports same-sex civil unions, not same-sex marriage - but has repeatedly suggested that his position is, which has been taken by same-sex marriage advocates as a sign that he will eventually come out in favor of same-sex marriage rights.
"I struggle with this," the president said in December. "I have friends, I have people who work for me who are in powerful, strong, long-lasting gay or lesbian unions. And they are extraordinary people. And this is something that means a lot to them and they care deeply about."
After Thursday's address, attendee Dennis Lonergan said he wished Mr. Obama had gone further in his comments on gay marriage.
"I thought it was a good speech but I would have preferred a more full-throated endorsement of equality and a more full-throated statement about the discrimination that we face," he said, adding that "I think that's how he feels."
"The people who are dead set against him, they not going to vote for him anyway no matter what he says about gay marriage," Lonergan continued. "And he could really take a stand and move the needle a bit and stop being coy about it."
Lonergan's partner, Sean Graves, said he thought the speech was "great," despite the "tough timing with everything that's going on in Albany."
"I appreciate, I think, the position he's in," Graves said. "...I think he could lead a little bit more, I wish he would lead a little bit more, but I'm extremely afraid of the alternative."
The gay rights movement has grown rapidly over the past decade, and coalesced into sometimes-competing factions: One that accepts incremental positive change (and largely supports Mr. Obama) and another (mostly younger) faction that has pushed for immediate action on marriage and other issues. Those in the latter group have heckled and protested the president over what they see as an unwillingness to fully fight on behalf of their civil rights. (At a recent liberal conference, activists booed an Obama intern who defended the president's gay rights record.)
"There's a very visible divide between the people walking in and the people who are protesting," said gay rights activist Lt. Dan Choi in an interview before the speech. "The young people who he needs aren't the ones wearing tuxedos. They're not the ones kissing the ring."
Choi, who is dismissive of backers of incremental change, cast the gala attendees as "rich, white older elites" whom Mr. Obama sees as "dollar signs." He said that if Jesus Christ were at the event, "he would be tossing tables" in frustration at the lack of progress on gay rights issues.
Outside the fundraiser Thursday, a crowd of about 50 protesters chanted "I am somebody. I demand full equality. Right here, right now."
Christin Meador, who helped organize the event, said her message to Mr. Obama is "evolve already," a reference to Mr. Obama's public statements about his position.
"It's time to evolve before 2012," she said. "Don't play politics with peoples' civil rights."
Mr. Obama has faced persistent accusations of flip-flopping on same-sex marriage tied to his response to a questionnaire from a gay newspaper in 1996, when he was a state Senate candidate. "I favor legalizing same-sex marriages," he wrote, adding that he would "fight efforts to prohibit such marriages."
But as a presidential candidate Mr. Obama said he supported civil unions, not marriage, and the White House has suggested he was referring to civil unions in his 1996 response. He has cast his opposition to same-sex marriage in religious terms, telling evangelical pastor Rick Warren in 2008, "I believe that marriage is between a man and a woman. For me, as a Christian, it is also a sacred union."
Coming out in favor of same-sex marriage carries political risk for the president. Rep. Barney Frank, the openly gay Democrat from Massachusetts, told the New York Times last week that he believes Mr. Obama sees same-sex marriage as "legitimate" - but that it "would have been an unwise thing to say" before the 2008 election.
And while the issue still carries that risk - in part because it means criticism of Mr. Obama for spotlighting social issues while the economy sputters - that calculation may have changed since then. Some polls suggest a slim majority of Americans now support same-sex marriage, and backers question why the president has yet to throw his support behind the issue.
"A Democratic president should be way ahead on this issue," journalist Michelangelo Signorile told Politico. "He is behind so many politicians in this country who are now leading the way on gay equality, and that includes some Republicans. ...When your position on something like this is behind Laura Bush, that is a problem."
In his remarks Thursday, Mr. Obama pointed to his administration's record on gay rights issues - chief among them driving the (as yet uncertified) repeal of the military's "Don't Ask, Don't Tell" policy and the decision to withdraw legal support from the Defense of Marriage Act.
The Obama administration has also granted benefits to domestic partners of federal workers, passed a hate crimes prevention law, lifted a ban on immigrants with HIV, extended hospital visitation rights to same-sex partners, and hired a number of LGBT Americans.
It adds up to by far the most pro-gay rights record of any American president, and Mr. Obama at times seemed frustrated that he was being pushed so hard, pointing to the "enormous advances" since he took office and noting he had been heckled at fundraisers over some of those issues in the past. He acknowledged, however, that "we have more work to do," adding that "there will be times where things won't be moving as fast as people would like."
"Yes, I expect continued impatience with me on occasion," said Mr. Obama. He added that "slowly but surely we find the way forward."
Actor Neil Patrick Harris, who hosted Thursday's fundraiser benefiting the Democratic National Committee and the Obama reelection campaign, pointed to Mr. Obama's record to argue that backers of gay rights should vote for and work on behalf of the president in the 2012 campaign cycle. But for Meador, the protester outside the event, it wasn't enough.
"Until people are treated equally," she said, "we're not going to sit at the table with you."