" hey at least Americans weren't degenerate enough to let themselves be ruled by fascists, they don't get it"

But they were degenerate enough to let themselves be ruled by a morally corrupt right-wing religious troop of neocon warmongers who lied to their own people and made sure American multinationals profited from the ensuing bloodbath though, weren't they?

I don't see any problem with Wainright's song - it's a purely personal polemic and in that respect like thousands of other songs expressing an opinion. It strikes a chord because many people feel threatened by the aggressive consumerist imperialism and military belligerence that has become a very prominent part of how the US is viewed across the world.