I think that until there is some sort of overarching story about American identity that bridges these gaps, the different factions in American politics are just going to become more entrenched and more polarized.
In the past, I always rolled my eyes a little bit about the emphasis in my country (Canada) on multiculturalism — more specifically, the way we constantly praise ourselves for how multicultural we think we are! I realize now that ideas like these are part of the glue that holds very different people and perspectives together. They make it possible for our sort of society (one where average citizens are far removed from the gears of political power) to function. When that breaks down — when people are longer buying in to the stories that describe how their societies are shaped — then we lose our way. And I think that is a significant factor in the decline of liberalism (or “enlightenment thinking” or whatever you want to call it) in America over the past decade.