Republican presidential candidate, former Massachusetts Gov. Mitt Romney, speaks as he participates in the NBC News, National Journal, Tampa Bay Times debate held at the University of South Florida on January 23, 2012 in Tampa, Florida. Chip Somodevilla / Getty Images

Republican presidential candidate Rick Santorum participates in the NBC News, National Journal, Tampa Bay Times debate held at the University of South Florida on January 23, 2012 in Tampa, Florida. Chip Somodevilla / Getty Images

Republican presidential candidate Ron Paul participates in the NBC News, National Journal, Tampa Bay Times debate held at the University of South Florida on January 23, 2012 in Tampa, Florida. Chip Somodevilla / Getty Images

Republican presidential candidate Newt Gingrich gestures during a Republican presidential debate Monday Jan. 23, 2012, at the University of South Florida in Tampa, Fla. Paul Sancya / AP