Celebratory Air at Obama Fund-Raiser for Gay Rights Supporters LOS ANGELES - Nearly a month after President Obama announced his support for same-sex marriage, on Wednesday night he got a rousing reception and at least $2.5 million at a gala of gay rights supporters and a private, celebrity-studded dinner afterward. Mr. Obama was introduced at the gala by an Army surgeon who benefited from the president's repeal of the "don't ask, don't tell" law against openly gay people in the military. And his appearance on the ballroom stage of a Beverly Hills hotel here provoked a long standing ovation and chants of "four more years" that Mr. Obama finally brought to an end after nearly two minutes. The celebratory air was a bit of a contrast with a similar gala in New York City a year ago, when Mr. Obama's mostly well-received speech to gay donors was repeatedly interrupted by hecklers in support of same-sex marriage and some attendees were visibly unenthusiastic. At the time, Mr. Obama supported civil unions and opposed marriage between people of the same gender, though he said his position was "evolving." Yet in Beverly Hills on Wednesday, it was not same-sex marriage but Mr. Obama's repeal in late 2010 of "don't ask, don't tell" that was the most prominent topic - just as it often receives the most applause at Mr. Obama's campaign events generally. Mr. Obama began by paying tribute to his introducer, Dr. Vito Imbasciani, who served three tours treating soldiers wounded in Iraq and Afghanistan, hiding the fact that he had a husband and two adopted sons at home. ("I kept their existence a secret, because that's what the law required. But not anymore," Dr. Imbasciani told the crowd.) And the president closed by grafting a new anecdote for the occasion onto what had largely been until that point his usual stump speech. Mr. Obama said that during his family's annual holiday visit to Hawaii last December, during his daily workouts at a military base, four times Marines interrupted to thank him for ending "don't ask, don't tell." On the day before he returned to Washington, Mr. Obama said, a "very fit" Marine approached. After first telling the commander-in-chief, "You're not doing that exercise right, sir," the Marine said to Mr. Obama, "I can't tell you how much it means to me that you repealed "don't ask, don't tell." " Mr. Obama said he assumed this Marine was gay, like the others before him, and asked him if he had been wrestling with the issue for long. "No, sir, I'm not gay," the Marine replied. It was important to me because I've had friends in my unit that were and I knew how much it tore them up, and I didn't think it was right. Mr. Obama, his voice rising, told his supporters, "I tell that story so that if anybody out there asks you what this campaign is about, you tell them it's still about hope and change." Only weeks ago, the annual fundraising dinner of Mr. Obama's LGBT Leadership Council, which he formed during his 2008 campaign for his lesbian, gay, bisexual and transgender donors, had loomed as a potentially awkward event as many of the supporters had grown impatient with his talk of a still-evolving position on same-sex marriage. But after Mr. Obama announced his support in early May, the gala had to be moved to the larger venue, the Regent Beverly Wilshire hotel, when demand for tickets spiked, organizers said. Among the roughly 600 attendees, who paid at least $1,250 each, were the openly gay comedian Ellen DeGeneres; Cher, the singer and actress, long popular with gay Americans, who has a transgender son, Chaz Bono; Jesse Tyler Ferguson, a gay actor who plays a married gay parent on the hit television show "Modern Family"; Darren Criss, who plays a gay student on the hit television show "Glee"; and Peter Roth, chief executive of Warner Bros. Television. About 70 people paid $25,000 each, or $40,000 a couple, to hear and question Mr. Obama at a private dinner that followed at the Beverly Hills home of Ryan Murphy, creator of "Glee," and his fiancé, the photographer David Miller. The actress Reese Witherspoon was there and, according to an Obama campaign official and organizers, so were the "Glee" star Jane Lynch and the actress Julia Roberts. Before Mr. Obama reached Los Angeles on Wednesday, he stopped in San Francisco for two fund-raisers: a private meeting with about two dozen donors from the technology field who contributed $35,800 each, and then a luncheon for about 250 supporters who paid $5,000 each. As usual, the proceeds from the California events benefit Mr. Obama's campaign, the Democratic National Committee and some state Democratic Party organizations.