South Carolina
Outlook: Strong Republican
It's not that Governor Mark Sanford is ultra-popular in South Carolina (although he has a respectable approval rating about 20 percentage points higher than his disapproval). It's more that Sanford is "popular enough" and the Democratic Party in the Palmetto State is dead in the water. Everyone who has been mentioned as a potential nominee would be trivial for Sanford, who may be destined for a Presidential campaign. The only thing keeping this from a safe designation is Sanford's previously mentioned approval ratings that are, while excellent, lower than what they usually are for an incumbent regarded as this safe.
I agree with you that this is a Strong, but not Safe Republican Seat. I would however mention that Sanford's weakness stems in part from infighting with Assembly Republicans. It'll be a little easier to handicap this race in a couple of weeks when the General Assembly session is over. State Senator
Tommy Moore is the leading Democratic contender and is likely to prove capable enough to derail Sanford's Presidential possibilities, even if Sanford is re-elected. Another possibility of how Sanford's hopes may be dashed is who ends up being elected as Lt. Gov. Incumbent
Andre Bauer is lightly enough regarded that his re-election is less probable than Sanford's. If Sanford has a Democrat Lt. Gov., he will likely be unable to gain the necessary support for a Presidential run.