American exceptionalism isn't just that the USA is great b/c it's the USA, but because it founded as an implementation of a set of moral ideals.

http://en.wikipedia.org/wiki/American_exceptionalism

As an American, I agree though, it is nauseating when politicians or citizens pull this card and use it to justify nationalism or other bad things and abuses. It cancels the very reasons for the idea of exceptionalism in the first place.