Why is the string of (if memory serves me) majority black towns/cities in the North of the state so disproportionally Romney-friendly? One would expect that the GOP in those towns would be even more than elsewhere the party of the white half of the population. Or are there a lot of democrats crossing over to vote in the primary over there?
The white parts of Columbia and Charleston are traditionally Republican, fairly wealthy and educated. This is the perfect formula for a Romney victory. The neighborhoods that went strongly for Romney are indicative of the type of place that voted for Ford over Carter in 76.
So: there were no crossovers but the GOP electorate is moderate and doesn't act very southern. Charleston voted for McCain against Bush in 2000.
There has always been a split in the SC GOP between the evangelical upstate, which tend to be poorer, less educated Republicans who favor social issues, and the more moderate low country. McCain won 44% in 2008 and McCain won the county in 2000.
Mitt won the Charleston city proper, resort towns and barrier islands but lost the poorer North Charleston and didn't play as well as McCain in the Myrtle Beach area. Mittens basically won the types of Republicans that are no longer in the GOP or leaving it in droves.
