White women have moved from 50-42 percent in Obama's favor before the conventions to 53-41 percent for McCain now, a 20-point shift in the margin that's one of the single biggest post-convention changes in voter preferences.

Some of McCain's biggest gains in this ABC News/Washington Post poll are among white women, a group to which "hockey mom" Sarah Palin has notable appeal: Sixty-seven percent view her favorably and 58 percent say her selection makes them more confident in McCain's decision-making. Among those with children, Palin does better yet. And enthusiasm for McCain among his female supporters has soared.

Before I get to that, let me explain what I'm not scared of, which is that Palin has somehow altered the demographics of the race. I have a hard time believing that female Hillary supporters, or Rust Belt men, are suddenly racing to support McCain because of Palin. For one thing, vice presidential nominees almost never attract demographic groups that the nominee can't attract on his own. People vote for the top of the ticket, not the bottom. More importantly, if that historical pattern somehow broke down this year, it would probably hurt the GOP ticket more than it would help. People may love Sarah Palin, but they don't think she's ready to be president.