Gay Marriage Effort Is Attracting a Novel Group of Donors LOS ANGELES - On a warm Friday afternoon three years ago, Rob Reiner, the director, arrived for lunch at the Beverly Hills estate of David Geffen, the entertainment mogul. Mr. Reiner and his political adviser, Chad H. Griffin, had spent six months drafting an ambitious legal campaign aimed at persuading the United States Supreme Court to establish a constitutional right of same-sex marriage. Mr. Reiner, joined by Mr. Griffin and Mr. Reiner's wife, Michele, told Mr. Geffen they would need $3 million to challenge Proposition 8, a California voter initiative approved the previous November banning same-sex marriage. He informed Mr. Geffen that they had recruited two renowned lawyers, David Boies, a Democrat, and Theodore B. Olson, a Republican, to argue the case. "Our feeling is not to go state by state," Mr. Reiner said. Our strategy is to make this wind up in the United States Supreme Court and have this a settled issue for all time. Mr. Geffen asked few questions as they sat in the dining room off his screening room, with a sweeping view down his sculptured estate. He agreed before the dessert arrived to raise the money. "I said I'd give them half the money and raise the other half," Mr. Geffen recounted. Mr. Geffen wrote a check for $1.5 million and asked Steve Bing, a friend and producer, to make up the rest. That lunch was a milestone in the dramatic evolution of a behind-the-scenes fund-raising network whose goal is to legalize same-sex marriage from coast to coast. This emerging group of donors is not quite like any other fund-raising network that has supported gay-related issues over the past 40 years. They come from Hollywood, yes, but also from Wall Street and Washington and the corporate world; there are Republicans as well as Democrats; and perhaps most strikingly, long-time gay organizers said, there has been an influx of contributions from straight donors unlike anything they have seen before. Mr. Griffin, who this month was named president of the Human Rights Campaign, a national gay advocacy group, recounted being at a September 2010 fund-raiser for the Proposition 8 legal fund at the Mandarin Oriental Hotel in New York, organized by, among others, Wall Street financiers and the former chairman of the Republican National Committee. "I knew literally no one in the room," said Mr. Griffin, whose fund-raising activities on behalf of the Obama campaign helped earn him a seat at President Obama's table at the state dinner at the White House last week. It was a very bizarre moment for me. It was really a turning point. Money does not always translate into political success, of course. While the network has bankrolled the legal case that led two courts to throw out Proposition 8 and also helped power a same-sex marriage bill to law in New York State, tough battles may lie ahead with marriage initiatives on five state ballots this year: Maine, Maryland, Minnesota, North Carolina and Washington State. And opponents say that while they might be outmatched financially - the National Organization for Marriage said it had an annual budget of about $20 million, and estimates that the combined money being spent in support of same-sex marriage is many times that - they have a more saleable message. Brian S. Brown, the president of the organization, said voters had opposed same-sex marriage in the 30 times the question has been on a ballot since 2000. "We know what we have to do to win," he said. We have shown we did not need to match them dollar for dollar. I would love to. But we've won without doing that. The seed money collected at the Geffen home - part of millions of dollars that have flown into campaigns to finance court battles, initiative efforts and the campaigns of sympathetic state lawmakers - was an early indicator of the changing donor network. Mr. Geffen is gay; Mr. Bing is straight. Mr. Bing is known as a big contributor to political causes, but associates said this was only the second time he had ever made a major contribution to a gay-related cause. The Republican support for the effort largely began after Mr. Olson, a solicitor general under President George W. Bush, lent it his name. It accelerated with the fund-raising role of Ken Mehlman, the former chairman of the Republican National Committee and of Mr. Bush's re-election campaign, who announced he is gay 18 months ago and has since helped raise close to $3 million by fishing in waters where gay organizers had rarely gone before. Ian Lovett contributed reporting from Los Angeles, and Kitty Bennett from St. Petersburg, Fla.