Conditional probability is subtle, part 2

Nate Silver returns to the idea of conditional probability: he's saying Pennsylvania is "in play" in this election, not because the polling in Pennsylvania is close, but because conditioned on the election being close, Pennsylvania is close. In general, I've heard quite a few people argue that the candidates should focus on the states that would be close if the election were roughly tied, not the ones that actually are close, because the details of which state a candidate deliberately tries to sway things in only matter in a close election anyway.

Unfortunately, subtleties like this seem to be lost on some of Silver's commenters.

In case you're wondering, my last post titled "Conditional probability is subtle" had nothing to do with politics.