don't know who this big 'you' that you keep referring to. Being that this country's population growth is significantly due to immigration (I believe the Washington Post suggested the figure of 40%, though I don't know precisely), I would argue that a great number of Americans have been exposed to the variation of the world.

Although I too have a significant problem with the black hat/white hat mentality of discourse, I would caution you to not take internet forum discussions and party-affilliated websites to be an accurate reflection of how all Americans think or speak. This is a very big country and there is a lot going on that isn't covered by the media.

Having lived in a dozen U.S. states and western Europe, and traveled throughout Asia, I am aware of diversity (and I am an American). I can tell you that a Wyoming rancher has as much in common with a New York City stock broker as a Swede has to do with an Italian.