Being completely technical here, I think our nation is mostly a nation of moderates. We're all very close to the center of the political spectrum and don't veer far from it, even if we do give the people across the isle a dirty glare. The only recent phenomenon is the fact that the media seems to be a lot happier to expose the more partisan bits of our public and in turn we all think that we stand miles away from our opposition in beliefs.
The blow up that occurred on facebook and other social media after the election results were announced was obnoxious. As much as we'd love to believe there were stunning differences, Romney and Obama were only swimming on different sides of the same pond, not on different sides of an ocean. We believe we're about ten times more partisan than we really are.