I'm going to go out on a limb and predict that the Democratic presidential campaign is not going to last until August, or even until June. It may not even last until the Pennsylvania primary in April.

Just yesterday, I noticed the following in a Roger Simon column in the Politico from last week:

“Under our projections, if you sat both the Michigan and Florida delegations as they now exist and based on our projections for the remaining contests, Sen. Clinton would still trail narrowly on pledged delegates going into the convention,” a senior Clinton aide told me Wednesday. “But it would be very narrowly, and that would make a difference.” (Later in the column, there's an indication that to "make a difference," the gap would be about 30.)

In other words, even the Clinton campaign can't see a path to a majority of pledged delegates. And since the 80 Clinton delegates from Michigan selected in a one-candidate primary are not going to be seated, whatever they think the narrow margin is, it's really much wider.

So the Clinton campaign's only hope is to be able to argue that a combination of momentum in the last few primaries, combined with winning the popular vote, would persuade the superdelegates to overrule a significant Obama edge in pledged delegates.

Whether enough superdelegates would see it this way or not, let's take seriously the question: Could Clinton win the popular vote?