I haven't but it wouldn't shock me. I typically don't get involved debate but I recall an incident when I was in middle school where we were asked to draw a comic strip and I drew a little gangster story and was yelled at in front of the class because it included some shooting.

I don't care what a teachers politics are, they shouldn't force their views on the kids (not that I'm saying that's what they are doing in this case) but the parents should also keep their cool too. Chances are, the kids just wanted out of class anyway. That would have been why I walked out if I was in school. I don't know people get too butt hurt over political disagreements, I think anyway. The kids will make up their own minds in the end, though. There's nothing anyone can do about that.