I think the answer is no–or, at least, he would not be likely to beat her if he jumped into the race. That’s not because she showed some newfound strength in this week’s debate. It’s because the Democratic party, elites and voters alike, decided it preferred her to him years ago, and decided it with full knowledge of her character. That’s why she was the heir apparent, not the sitting vice president. They prefer her because she’s a woman, and because, whatever their other reservations about her, they do not worry that she has any tendency to be a buffoon.

There are only two things that could make Democrats reconsider their decision. Clinton could break with one of the party’s core commitments. Or Democrats could come to believe that she is likely to cost them the White House if nominated. The first is not going to happen. The second has not happened: Democrats believe they are well-positioned to keep the White House with her as the nominee (and as I argue in the new issue of NR, they have some objective basis for this belief). If Democrats thought Clinton was a sure loser, Biden could run as the guy who would rescue them from defeat. Otherwise he will have to run as the guy who wants to stop the election of the first female president. That wouldn’t go over well. He would probably lose. He would inflict some damage on her general-election chances, because his campaign would have to be based on highlighting her flaws rather than on the picayune ideological differences between them. And because he would be standing in the way of the first female president and the likely Democratic nominee, he would probably hurt his own reputation among Democrats.

So it’s not in his interest to run.