I've never been to Alabama myself, so I don't know whether this is actually true or not. I suspect it wouldn't be as bad as he's implying (it might start an argument, but I wouldn't expect a fight), but that might be my optimism acting up.

Maybe it's just because I'm a New Yorker, but trust me that you don't have to cross the Mason-Dixon line for people to be willing to sock someone who said something even remotely positive about the 9/11 hijackers. Things have cooled down a bit in the last twelve years, but there are still some things you just don't say. Or imply, in this case.

I know that I would personally have trouble restraining myself if someone expressed actual support for, or tried to equivocate-away, the crimes of terrorists in my presence. It's absolutely an issue of tribal loyalty, and not even entirely irrational; expressing empathy for an enemy weakens your resolve against them, which is not a particularly wise choice when the only way our tribe can lose is by giving up.