There's an outside chance the Democrats might pick up the governor's mansion, but I doubt Democrats will hold any other statewide office in South Carolina for a long time, nor will they pick up seats in the legislature (I believe they've lost one or two seats in special elections since 2008).
The Republicans are going to hold the Governor's mansion, trust me.
Hence why I said "outside chance". With all the troubles and the closest thing to a top-tier recruit for the Democrats (Jim Rex) there's a chance of an upset, but it's a small one.