** FILE ** Republican presidential hopeful Rick Santorum greets his audience at a gathering Tuesday on the USS Yorktown in Mount Pleasant, S.C. He is trying to convince voters in the run-up to the state's primary Saturday that he is the best conservative in the race. (Associated Press)

** FILE ** Republican presidential hopeful Rick Santorum greets his audience at a gathering Tuesday on the USS Yorktown in Mount Pleasant, S.C. He is trying to convince voters in the run-up to the state's primary Saturday that he is the best conservative in the race. (Associated Press)