Former Massachusetts Gov. Mitt Romney (right) and former Pennsylvania Sen. Rick Santorum argue a point Feb. 22, 2012, during a Republican presidential debate in Mesa, Ariz. (Associated Press)

Photo by: Jae C. Hong

Former Massachusetts Gov. Mitt Romney (right) and former Pennsylvania Sen. Rick Santorum argue a point Feb. 22, 2012, during a Republican presidential debate in Mesa, Ariz. (Associated Press)