George Clooney, Barack Obama, and Jeffery Katzenberg. (Getty Images)

Updated Friday: Read a detailed account of the night on the Election 2012 blog: Obama hangs with Clooney in L.A, 5/11/12

Looks like Hollywood’s love affair with President Obama is back on — in a big way. As in a $12 million fundraiser at George Clooney’s L.A. mansion Thursday night.

The party, shaping up to be the largest single presidential fundraiser in U.S. history, was a hot ticket before Obama’s public support for same-sex marriage — an important issue for many heavy hitters in the entertainment industry. Now Clooney’s sold-out event is expected be a victory party for A-listers lucky enough to make the cut.

Obama has always enjoyed a cozy relationship with Hollywood’s power players: In 2008, Steven Spielberg, David Geffen, Barbra Streisand, Leonardo DiCaprio, Jodie Foster, Eddie Murphy, Chris Rock, Larry David, Garry Marshall and many more threw their support to the Democratic nominee. Will Smith, Magic Johnson, Antonio Banderas, Melanie Griffith, and Eva Longoria held re-election fundraisers last fall; Will Ferrell hosted a February $35,800-per-person event, featuring the Foo Fighters at the estate of soap opera moguls Bradley and Colleen Bell.

Will Farrell in Mexico City last month. (Eduardo Verdugo/Associated Press)

(Update: Katzenberg told the New York Times he believes the dinner will raise $15 million — a number also cited by a “top Democratic source” to CNN — but campaign officials said that amount was too high.)

The other headline from the party? Obamajam, the name coined for limolock and the presidential motorcade. Big issue for Clooney’s neighbors, who have another reason to hate driving in L.A.

“From 3 p.m. to 6 at night, traffic in the Valley doesn’t move anyway,” Eric Bauman, chairman of the Los Angeles County Democratic Party told L.A.’s Daily News. “Having the president here won’t be any different than any other rush hour.”