If foreign visitors get treated even half as poorly as I've been treated, and I'm sure they do, it's an embarrassment. I wish more Americans traveled overseas because if they experienced the difference between how we treat people vs how others do, they'd be properly outraged.
I stopped bothering even being polite to them after getting repeatedly questioned about my travels when I trying to get back home before my mother died. I'll be the first to admit that I often have trouble showing empathy, but these people make me look like a saint.