Rick Santorum Mitt Romney

Rick Santorum Mitt Romney

Alex Wong/Getty Images

Republican presidential candidates, left to right, former Utah Gov. Jon Huntsman, former U.S. Sen. Rick Santorum, former Massachusetts Gov. Mitt Romney, and U.S. Rep. Ron Paul (R-TX) participate during the NBC News Facebook Debate on 'Meet the Press' on Jan. 8, 2012 at the Capitol Center for the Arts in Concord, New Hampshire.