According to the “entrance poll” reported in the New York Times, Obama was as popular among women as among men (35 percent in both cases), but there was a huge generational gap. Among voters under 30, Obama won 57 percent of the poll’s respondents, compared with Edwards’ 14 percent and Clinton’s 11 percent. With voters over 65, however, Clinton won 45 percent of the vote to Edwards’s 22 percent and Obama’s 18 percent. There was a three-way tie among married voters, but Obama had a 20-point lead among singles; Clinton and Obama were tied among voters making less than $50,000 a year, but Obama had a 13-point lead among more affluent voters.

New Hampshire has a slightly older population than that in Iowa (a median age of 39.4, versus Iowa’s 37.8), so the youth vote may not be quite as helpful for Obama. At the same time, however, a lower share of the population is over 65 (14.6 percent in Iowa, 12.4 percent in New Hampshire), so Clinton can’t expect to win based on the retiree vote.

In the Republican poll, Huckabee beat Romney by only 3 points among men, but 16 points among women. The age gap was not as strong as it was among Democrats, but younger voters prevailed here as well. Huckabee beat Romney 40-22 among voters under 30 (with Ron Paul’s 21 percent making him a close third), but he beat Romney by only two points, 30-28, among people over 65 (with McCain’s 21 percent giving him third place).

The New York Times also has a map of the Iowa caucus results by county, which unfortunately does not use very distinct colors. Last week I highlighted the largest counties where the November vote for president trended toward or away from George W. Bush between 2000 and 2004. There is no clear pattern on the Republican side, but Obama did noticeably better in counties where Bush failed to improve his percentage as the (post 9/11) incumbent; he was not quite as strong in counties where the Democratic Party lost votes between 2000 and 2004. This suggests that he may have better luck bringing new voters into the electorate if he is the nominee, rather than getting back voters who switched to the Republicans last time.