Chris Carlson / Pool via AP
Republican presidential candidates are greeted by former first lady Nancy Reagan, center, before a Republican presidential candidate debate at the Reagan Library Wednesday, Sept. 7, 2011, in Simi Valley, Calif. From left are, former Pennsylvania Sen. Rick Santorum, former House Speaker Newt Gingrich, Rep. Michele Bachmann, R-Minn., former Massachusetts Gov. Mitt Romney, Texas Gov. Rick Perry, Rep. Ron Paul, R-Texas, businessman Herman Cain and former Utah Gov. Jon Huntsman.