If I'm not mistaken, SC almost voted for Ike twice and barely voted for Carter. When you consider that it had Strom Thurmond who flipped to the GOP well before Republicans had power in the South (say what you want about civil rights, there were MANY more segregationist Democrats who remained in the party until the day they died), it seems they've always been more conservative than their neighbors (or at least post-New Deal).
The fact that South Carolina underwent a similar political evolution to that of Virginia or Florida rather than Mississippi or Alabama seems to suggest that it will become Democratic sooner than most other Southern states.
I expect we will see an lowland vs. upland dynamic emerge in the Palmetto State, with the Black Belt and the Coast becoming overwhelmingly Democratic while the Greenville area remains staunchly conservative.
