If Hillary Clinton can eke out a win in either Texas or Ohio, a 2-1 majority of Democrats nationwide want her to remain in the race, according to a fresh ABC poll. The 29% who want her to withdraw if she doesn’t win both increases to 51% if she loses both. That doesn’t exactly give a ringing endorsement to Barack Obama, who may wonder why a 13-state win streak isn’t enough for 45% of Democrats:

Democrats by more than a 2-1 margin say Hillary Clinton should stay in the presidential race even if she loses either the Texas or Ohio primary on Tuesday. But if she fails in both, fewer than half say they’d want her to fight on.

Many, in that case, have another idea for Clinton: the vice presidency.

The lead overall is now Barack Obama’s. With his string of 11 consecutive primary and caucus victories, Democrats and Democratic-leaning independents by a 50-43 percent margin would like to see him nominated. That’s a remarkable reversal: Clinton held a vast lead in ABC News/Washington Post polls before the Iowa caucuses. Campaigns clearly matter.

Despite the overall preference for Obama, Democrats by a very wide 67-29 percent say Clinton should stay in the race even if she loses either Texas or Ohio. But if she were to lose both, far fewer say they’d want her to continue 45 percent, with 51 percent saying otherwise.

The key demographic in that statement is independents — or at least it used to be. Party members no longer favor Hillary, as Obama now has a 10-point advantage among Democrats. Interestingly, ABC has Hillary leading among independents by two points. Otherwise, Obama owns most of the rest of the categories, including a whopping 22-point advantage among men. Clinton still leads by 10 among whites, and by 25 points among white women.

What does this mean for tonight? It means that the Hillary campaign has no reason to shut down after tonight, and it will extend her campaign to Pennsylvania at the very least. She leads in Ohio, maintaining an advantage there as Obama has floundered in the past few days over NAFTA and Rezko. Only Zogby shows Obama coming close, and that’s hardly the most reliable pollster in the business. All of the other polls have Clinton ahead outside the margin of error.

As for the vice-presidency, forget it. Hillary won’t be a second banana again in a Democratic administration, and after her remarks on Obama’s “experience”, he won’t choose her anyway. However, ABC’s poll on a running mate for John McCain looks interesting. Seventeen percent want Mike Huckabee, and 11% want Mitt Romney. “Other” outpolls Romney at 13%, while 43% don’t care at all. Obviously, the VP selection is hardly a make-or-break moment for McCain, a somewhat surprising result given his issues with the base and the supposed angst over his age.

My prediction: Clinton wins Ohio by six, and Obama wins Texas by three. They’ll split the other two states, and wind up with a push in delegates overall. And it will be enough to keep Hillary in the race. I’ll be live-blogging the results tonight, so be sure to check back starting at 6 pm CT on a new post.