Republican presidential candidate and former Massachusetts Gov. Mitt Romney (left) walks Feb. 26, 2012, with Florida Lt. Gov. Jennifer Carroll before the NASCAR Daytona 500 Sprint Cup series auto race at Daytona International Speedway in Daytona Beach, Fla.. (Associated Press)

Republican presidential candidate and former Massachusetts Gov. Mitt Romney (left) walks Feb. 26, 2012, with Florida Lt. Gov. Jennifer Carroll before the NASCAR Daytona 500 Sprint Cup series auto race at Daytona International Speedway in Daytona Beach, Fla.. (Associated Press)