Innumeracy: Karen Tumulty: "Are polls getting thrown off by the fact that so many young people use cell phones only--and, therefore, don't get polled? The answer: Possibly, though the effect is probably small."

Well, sure, if by "small" you mean "big enough to have changed the results in each of the last two presidential elections."

Speaking of numbers, you guys are all reading Nate Silver, right? Here he is on that totally trivial cellphone effect, which by the way means some national polls have a 3-point bias toward McCain. Silver's Todays Polling column [hits a slam dunk/kicks it out of the park/insert sports metaphor for triumphant scoring of your choice] every day, e.g.