Red states are states that voted for Obama & have a population density above the national average, blue states are states that voted for Romney & have a population density below the national average, green states are states that voted for Obama & have a population density below the national average, & yellow states are states that voted for Romney & have a population density above the national average. The shading is based on the overall population of the state, with darker states having a higher population.
I'm pretty sure North Carolina should be yellow here. There's no way it's less dense than, say, Alabama and Kentucky.
Yeah, Wikipedia has NC at 198.2 p/miČ and the US at 88.08 p/miČ.