My two cents: Obama is a big-city, cosmopolitan liberal and the bulk of the Republican base is from rural, ethnically/culturally homogenous regions where everyone else you know is probably just as conservative as you are. It isn't until you've moved from a liberal area to a conservative area that you realize that there really is a pretty big difference in what is regarded as the "average" American experience. It isn't just Obama - Republican voters genuinely do not like the denizens of urban areas and (in complete defiance of how math works) think that they subsidize their big city lifestyles with their tax dollars.
The "Average American" experience is very different between Philadelphia and the backwoods of Pennsylvania.
America's great cities are cosmopolitan. Some parts of America are "Dogpatch".
