U.S. Republican presidential candidates Paul and Romney listen to Santorum during the Republican presidential candidates debate in Mesa

 
U.S. Republican presidential candidates Paul and Romney listen to Santorum during the Republican presidential candidates debate in Mesa
U.S. Republican presidential candidates U.S. Rep. Ron Paul (R-TX) (L) and former Massachusetts Governor Mitt Romney (R) look on as former U.S. Senator Rick Santorum speaks during the Republican presidential candidates debate in Mesa, Arizona, February 22, 2012. REUTERS/Joshua Lott (UNITED STATES - Tags: POLITICS ELECTIONS TPX IMAGES OF THE DAY)