As the race heads into the fourth quarter, top Hillary advisers and supporters are wrestling with a big question:

Is it really politically feasible for her to continue to try to woo super-delegates in the event of a loss in both the pledged delegate count and the popular vote?

Some Hillary advisers and supporters now appear to be concluding that the answer is No. Without a popular vote victory to offset Obama's expected victory among pledged delegates, they say, it will be difficult indeed to make a case to super-dels that they should support her.

One Hillary adviser confirmed to me that he believes that if she falls short in the popular vote, it will become very tough to continue making the case to super-delegates that they should decide their choice based on electability alone, though this adviser said that an unexpectedly big string of victories could conceivably shift the dynamic somewhat.

Says another adviser: "It's much harder to make the case to super delegates without the popular vote. You have to give the super-delegates something to work with. You have to give them political cover to support her in opposition to what the pledged delegates represent."

Hillary spokesperson Howard Wolfson would only say: "The popular vote is an important metric that automatic delegates will look at in making their decisions."

Top Hillary Supporters Start Publicly Saying She Needs Popular Vote Win

For the first time today, some of Hillary's top supporters started publicly acknowledging that she needs a popular vote victory. In an interview with The Huffington Post, prominent Hillary surrogate and Pennsylvania Rep. Jack Murtha flatly predicted that without a popular vote victory, she would lose.

"She has to be ahead in the popular vote to have any chance at all of getting this nomination," Murtha told HuffPo.

Also this morning, Senator Jon Corzine, another prominent Hillary backer, said it would be very tough to woo super-dels without a popular vote win and suggested that if she didn't secure one, he might switch his backing to Obama.

There appears to be some dissent on this point within Camp Hillary, however. The other day, senior Hillary adviser Harold Ickes told me in an interview that while a popular vote win was "important," it wasn't "dispositive" or "absolutely critical."

Still, my sense from talking to Hillary insiders is that they are growing very gloomy indeed about the prospect of pressing on without a popular vote win.

Hillary Needs Florida And Michigan

This, in turn, is why the speculation we've been hearing that Camp Hillary secretly doesn't want Florida and Michigan resolved, in order to keep confusion alive, strikes me as off base. Her only real hope seems to be to close the popular vote deficit with Obama, so she can point to at least one metric suggesting that the people chose her. With a little luck this might dilute Obama's pledged del win and make it easier for Hillary to argue that super-dels should be free to use their judgment.

Though opinions on this vary, without somehow counting Florida and Michigan, catching him in the national popular vote seems borderline out of reach. And whatever "confusion" may continue to reign if Florida and Michigan remain unresolved, it won't stop the supers from bolting to Obama should this end with him leading by the pledged delegate count and the popular vote.

So Camp Hillary desperately needs Florida and Michigan -- which is why Hillary supporters have their Florida and Michigan rhetoric on full boil right now.

"No matter which candidate you support for the Democratic nomination, the nominee has to reflect the will of the people, and that cannot happen without Florida and Michigan," says Robert Zimmerman, a prominent Democratic National Committee-man and Hillary backer. "It is scandalous and a tremendous disservice to the Democratic nominee to evaluate the popular vote while disenfranchising two of the most critical states in this process."

At any rate, my bet is we'll be hearing more Hillary supporters in the days ahead asserting that without a popular vote win, her candidacy may be doomed.