George Clooney, Brad Pitt lead all-star Prop. 8 play reading With George Clooney and Brad Pitt leading the charge, the gay-marriage play "8" had its L.A. debut Saturday in a splashy event that was part activist theater, part Hollywood in-party. The sky-high celebrity factor no doubt helped to fill the Wilshire Ebell Theatre to near capacity for the one-night benefit performance, even if it made "8" feel something like "Ocean's Eight." Clooney and Pitt played a lawyer and a judge, respectively, in this dramatization of the 2010 court case Perry vs. Schwarzenegger, which challenged the legality of Proposition 8, the ballot measure banning same-sex marriage in California. Saturday's staged reading -- in which actors read from scripts on a courtroom set -- featured a 20-member cast that included Kevin Bacon, Martin Sheen, John C. Reilly, Matthew Morrison, Jane Lynch, Jesse Tyler Ferguson and Matthew Bomer. Dustin Lance Black, the Oscar-winning screenwriter, wrote "8" relying largely on transcripts from the trial. The play, which had a reading in September in New York, condenses 12 days of court hearings into a running time of less than 90 minutes, alternating between witness testimony and biographical scenes of the plaintiffs. The performance served as a benefit for the American Foundation for Equal Rights, the nonprofit group that spearheaded the court case against Proposition 8. Black and Rob Reiner, who directed the reading, serve as board members of the group. In a brief interview before Saturday's performance, Black said that he had made changes to the script since the New York performance, excising some of the legal scenes that he felt were repetitive and creating domestic scenes with the plaintiffs -- Kris Perry (Christine Lahti) and Sandy Stier (Jamie Lee Curtis), and Paul Katami (Morrison) and Jeff Zarrillo (Bomer). The cast had an extremely brief rehearsal schedule. The actors met for the first time earlier the same day for two run-throughs before the evening performance. Reilly played David Blankenhorn, head of the Institute of American Values and a proponent of Proposition 8. The actor was originally cast as Judge Vaughn Walker. But when Pitt became available, he took the role of Blankenhorn, which was supposed to be played by Reiner. In a scene that provoked abundant laughter from the audience, David Boies (Clooney), an attorney for the plaintiffs, attempts to dismantle Blankenhorn's testimony. Reilly, who portrayed his character as awkward and ill-at-ease on the witness stand, said in an interview after the show that he didn't do much research on his character. "I don't even know what he looks like," he said. Rory O'Malley, currently on Broadway in "The Book of Mormon," played Gregory Herek, a psychologist testifying for the plaintiffs. The actor said he flew in from New York on Friday and will return to the Broadway musical early next week. O'Malley is a founder of Broadway Impact, an activist group that co-presented Saturday's reading. Lahti, who also appeared in the New York reading, said the revised version of the play "took away some of the legalese and made it more fun" for the actors playing the plaintiffs. "Glee" actor Chris Colfer said he researched and watched interviews of his character, Ryan Kendall, a witness for the plaintiffs who testified about his experience in gay conversion therapy. A spokeswoman for the American Foundation for Equal Rights said the play reading was expected to raise more than $2 million for the organization. She said the performance drew an audience of approximately 1,200 people. The foundation spends most of its money on legal costs, according to tax documents. In the fiscal year that ended in March 2010, the group's legal expenses amounted to $2.1 million. It paid $1.7 million in fees to the firm of Gibson, Dunn & Crutcher, which was hired to fight the Proposition 8 battle in court. The group also has retained the services of the law firm Boies, Schiller & Flexner. The foundation differs from other gay-marriage groups, such as Equality California, which have used pro-bono legal services in the past. In February, a U.S. appeals court upheld Judge Walker's decision declaring California's ban on same-sex marriage to be unconstitutional. But the case is expected to be appealed and could end up at the U.S. Supreme Court. Saturday's audience included a handful of Hollywood power players and actors, including Barbra Streisand, Disney Chairman Rich Ross and Creative Artists Agency's Kevin Huvane, who represents Clooney and Pitt. Billionaire Eli Broad attended the performance with his wife, Edythe. "I'm here so that means I support what they're doing," he said after the show. He also said that he thought Reiner "did a fantastic job directing." The performance was broadcast live online via YouTube and can be viewed in archival form on the foundation's website. The 2010 court case was originally intended to be shown on YouTube, but the broadcast was blocked at the last minute. Gavin Newsom, California's lieutenant governor, said in an interview before the show that he believes same-sex marriage should be a federal issue. "I think it belongs in the Supreme Court," said Newsom, who has been an active proponent of gay rights. We can't have a patchwork of states deciding this issue. Photo: George Clooney, left, Martin Sheen and Brad Pitt are shown in a scene from the play "8," at the Wilshire Ebell Theatre. Credit: Jason Merrit / Getty Images for the American Foundation for Equal Rights