Marc Ambinder offers some helpful analysis of the spate of recent national polls. Although he does not quite put it this way, his reading seems to confirm the view that this election will be about whether the public finds Barack Obama adequate — if he passes a kind of minimal bar, he will win. If not, McCain wins. It’s an up or down vote on Obama more than a choice among alternatives. So far, some crucial constituencies remain unpersuaded, and Obama is underperforming in ways that ought to worry his campaign (and that apparently do worry them: notice especially their focus in the past day or so on “women’s issues” — which, perhaps with a touch of nostalgia, they apparently define as abortion, “equal pay,” and children’s health insurance.) But as Ambinder points out, these voters are still open-minded. I think he’s right in saying “they are ready to be persuaded, as opposed to waiting to be dissuaded.” Not an ideal situation for McCain, to be sure, but it could certainly be a lot worse in a year like this one. And of course, these are national polls. If you look at the crucial states individually, especially Pennsylvania and the upper Midwest, the problems that emerge for Obama in the national polls are all the more serious, and McCain’s chances are even better. There are some very plausible paths to victory for McCain, most of which would have been pretty surprising a few months ago.