Former Massachusetts Governor Mitt Romney (L) and Texas Governor Rick Perry are shown before the Reagan Centennial GOP presidential primary debate at the Ronald Reagan Presidential Library in Simi Valley, California September 7, 2011. Republican rivals Perry and Romney exchanged sharp jabs over who has the better job-creating record on Wednesday in a presidential candidate debate that featured the anemic U.S. economy at center stage. REUTERS/Mario Anzuoni (UNITED STATES - Tags: POLITICS)