Julianne Moore has recently played an adulterous lesbian mom and Alec Baldwin’s Boston-based childhood love on 30 Rock, but is she up for her biggest challenge yet? The actress has signed on to play Sarah Palin in HBO Films’ Game Change, based on Mark Halperin and John Heilemann’s 2010 book about the 2008 presidential elections. The film follows John McCain’s campaign, from choosing Palin as his running mate to the Republican duo’s defeat. Game Change’s script comes from Danny Strong, who also penned HBO’s Recount, about the aftermath of the 2000 presidential elections. Recount’s filmmaker Jay Roach will serve as Game Change’s director and executive producer.