Republican presidential candidate and former Pennsylvania Sen. Rick Santorum pumps his fist Feb. 21, 2012, during a campaign stop at the Maricopa County Lincoln Day Luncheon in Phoenix. (Associated Press)

Photo by: Eric Gay

Republican presidential candidate and former Pennsylvania Sen. Rick Santorum pumps his fist Feb. 21, 2012, during a campaign stop at the Maricopa County Lincoln Day Luncheon in Phoenix. (Associated Press)