I guess this can be put back to test in 2012.
Gov Palin vs President Obama.
Or Romney or Huckabee, former Governors. If you believe the pattern, no Senator has a real chance of defeating Obama even if Obama proves as incompetent as George W. Bush. Senators have records, and those records can usually be examined for legislation that doesn't look good after the fact. Seemingly every bill has something nasty in it, some detail that can be morphed into a monstrosity, so every Senator has a skeleton in the closet. Governors can always delegate the details; Senators can't.
Unless a Governor is Ray Blanton (pardons scandal) or Rod Blagojevich (attempted sale of public office) the most controversial thing that a governor can do as governor is to make controversial statements suitable only for local consumption. Heck, George Wallace might have become President had it not been for his segregationist stances.
Governors don't get free rides if they get entangled in controversy.
