Us vs Them and the Ad Hominem Defense

I mentioned this in a comment to Amp's post about the "ad hominem defense," but then I decided it was worth a full post. An ad homiem defense is when a liberal rattles off their lefty credentials in response to some specific criticism from the left (or mutatis mutandis for any other ideology). There's a particularly egregious example at the end of this Hank Fox post. Fox came in for a lot of criticism for saying that he wouldn't eat at an Arby's where one of the employees had a facial piercing, because he finds piercings disgusting. (In the linked post, he tries to defend himself by claiming that his problem is that people with piercings care too much about what others think, as if the clean-cut and wholesome look isn't just as much a show put on for others, and as if his vocal boycott of Arby's isn't essentially a demand that other people should care what others think about their appearance.) After his painfully self-righteous rationalization, Fox hauls out his liberal bona fides to prove that his anti-piercing views couldn't possibly be a case of bigotry.

Fox's post is interesting to me because it makes so clear one important element of the ad hominem defense: its use of the Us vs Them frame. He asks us to imagine a room full of people, and reminds us that if Rush Limbaugh and his ilk were on one side of the room, he and his critics would end up together on the opposite side. This is a vision of politics in which there are only two camps. Criticism may only be made against the other camp. If someone's liberal enough to get into the liberal camp, then they're one of Us. If you criticize someone, you must be implicitly seeing them as one of Them, an enemy on the same level as Rush. The choice is between total solidarity and total animosity. The only debate is over where to draw the line -- to we, like the users of the ad hominem defense, draw a magnanimously wide tent in order to focus on our real enemies on the far right? Or do we, as ad-hom-defenders' critics are assumed to, draw the line narrowly to include only a pure in-group on the "Us" side?

But of course this is not how politics works. So far as I know, nobody who criticised Fox's views of pierced people thinks that he's therefore wholly in Rush Limbaugh's camp. As I said to Hugo Schwyzer a while back,

... a person's membership in the cause is never all-or-nothing. Your sins don't wipe out the other good work you've done, but the other good work you've done doesn't earn you indulgences.

I think the mentality behind the ad hominem defense goes some way toward explaining why white people are reluctant to engage in deep discussions of race (and men in discussions of feminism, etc.) -- and I don't claim that I'm immune to this. There's a fear of discovering that while you thought you were one of Us, you are actually one of them. It's easier to pretend that race doesn't exist than to risk feeling lumped in with the KKK because you said or did something racially insensitive. Strategies like the "don't you have bigger fish to fry" argument that Amp discussed serve to keep the fundamental line between Us and Them in a comfortable spot. (Note that this is a problem with the assumptions privileged people make, not with anything that their critics are doing.)