It benefits Romney most, as an early removal of the turds from the punchbowl that is the Republican Party (Cain, Bachmann, Gingrich, Santorum and Perry) will give more time for the average voter in the general election to forget what was floating there, and all the stupid stuff that Romney had to say to get the 'bagger vote.
After he drives the opposition off, Romney can stop spouting the nonsense that appeals to the yokels, hicks, kluxers and blatherskytes.