In 2004, USA Today made a splash when they published a map of America showing which counties went for Bush versus Kerry. Although the election was quite close, the map made it clear that — geographically, at least — America was almost all “red.”
Republicans, at the time, used this map to argue that the vast majority of “real” America was with them — that only effete city slickers (mostly on the coasts) liked Kerry.
Over at the Washington Post, our friend Aaron Blake has posted some state maps, which I think demonstrates that a similar phenomenon is at play in the Republican primary. Romney performs very well in population-rich cities, but very poorly in rural areas. It’s basically the 2012 version of John Kerry’s map (except Romney is “yellow,” not blue).
Here’s South Carolina: