Townhall blogger Dean Barnett gives a prickly “FAQ” on polls. I don’t know the background behind the first couple of points, and I don’t really care to know ? the list made me laugh in places, but what made me decide to post this were his points nos. 11-12:

At the risk of being overly snarky, one of the reasons that liberals are being over-sampled is because as a group they?re more likely to be big-mouths; they?re more passionate about sharing their opinions and viewpoints with strangers. As a rule of thumb, conservatives aren?t as prone to such behavior.

12) Strange sentiment for a conservative blogger to have. Anyway, it sounds like a crass stereotype to me. Can you back it up?

With statistics, no. But I can give you an irrefutable piece of anecdotal evidence. Ask yourself how many cars you?ve seen today with a bumper sticker that said ?Kerry? or has a W with a slash through it or boasts some other hackneyed liberal sentiment. And then ask yourself how many cars you?ve seen whose owners have decided to festoon their automobiles with conservative sentiments of a similar sort. I?d wager that even if you live in the reddest part Texas, you?ve seen a lot more liberal cars today than conservative ones.

Barnett describes a phenomenon that I, as an occasional commentator on “liberal” bumper stickers, have long noticed. “Liberals” love to cover their vehicles with bumper stickers (and by cover, I mean not just stickers on bumpers, but stickers on windows and even on the paint). I hadn’t put much thought into why that is (my suspicion was that perhaps it helps them assuage their guilt for riding around in something that makes Mother Earth get angry and hurl hurricanes at poor black folks) ? but I had developed a little rule of thumb. I call it the Rule of Three: a car that has three or more bumper stickers will belong to “liberal.”

This rule has proven very reliable over the years. The only exceptions I’ve seen are cars that belong to pro-lifers ? they will occasionally have three or more pro-life stickers. But those tend not to be as condescending and self-satisfied, and only occasionally as shrill.