Sean Carroll in Preposterous Universe:
The idea of “red states” and “blue states” burst on the scene during the 2000 U.S. Presidential elections, and has a been a staple of political commentary ever since. But it’s become increasingly clear, and increasingly the case, that the real division isn’t between different sets of states, but between densely- and sparsely-populated areas. Cities are blue (liberal), suburbs and the countryside are red (conservative). Why did that happen? How does it depend on demographics, economics, and the personality types of individuals? I talk with policy analyst Will Wilkinson about where this division came from, and what it means for the future of the country and the world.
More here.