How will it all end?

With wins in Texas, Ohio and Rhode Island, the momentum this morning may belong to Hillary Clinton. But thanks to Democratic Party's gratuitously fair system, the delegate count barely changed after last night's white-knuckle victories--meaning the math still favors Barack Obama. Unless 30 percent of his superdelegates vanish, 30 percent of his pledged delegates defect and Clinton wins 60 percent of the remaining primary and caucus delegates, it's all-but-certain that he'll maintain his 150-delegate lead at the end of voting. No one doubts that Clinton will keep campaigning--at least through Pennsylvania on April 22, if not the Denver convention in late August. But it's still pretty tough to see a way--short of some serious superdelegate arm-twisting--for her to battle back to the White House.

Unless, of course, she battles back as second in command.

Vice President Clinton. I've always thought this hypothetical was a little loony; the CW is that both Clinton and Obama would need a soothing, centrist white male to balance out their new-fangled bids. But then I caught the New York senator this morning on CBS's "The Early Show," where she was asked, point blank, whether she and Obama should be running mates. Her response: "That may be where this is headed, but of course we have to decide who is on the top of the ticket. I think the people of Ohio very clearly said that it should be me."

Whoa, nelly. Forget everything but the first seven words; the rest is Clinton enjoying her victory lap. "That may be where this is headed." Translation: Clinton absolutely, undeniably, irrevocably confirmed that a joint ticket is a real possibility--implying, of course, that she would consider running alongside Obama. Speaking to reporters in San Antonio this morning, Obama refused to speculate. "I respect Sen. Clinton," he told the traveling press pack. "[But] it is premature to talk about a joint ticket."

Premature, perhaps. But could it happen? Neither Obama nor Clinton is especially excited about the prospect. In accepting the second slot, the Illinois senator would essentially agree to serve, if elected, as the most marginalized, impotent veep in history--remember, a rather influential fellow named Bill Clinton would again stalk the halls of the White House. And something tells me that Hillary would have a tough time taking orders from a man who's not "ready to lead on Day One," as she never tires of reminding us.

But the electoral math is hardly as dire as the pundits once predicted. Clinton would shore up the base, Obama would attract moderates and together they'd make life pretty difficult for John McCain; the distinct, durable factions of the Democratic Party would be united and ready for war. If this bloody battle continues through the convention--and it looks like it may--a joint ticket may emerge as the least painful resolution. "Obama cannot ignore her demographic coalition, her breadth and depth of support, the energy that she generates," writes the Atlantic's Marc Ambinder. "Just as Hillary surely cannot ignore--would not ignore--everything that Obama has come to stand for and has accomplished."

Here's how it could play out. Imagine that Obama clings to his leads in the popular vote and pledged-delegate count through the end of primary season--a near-certain outcome--while Clinton closes out regulation with wins in Democratic strongholds and battleground states like Ohio, California, New York and Pennsylvania. Reluctant to overturn the will of the people, the superdelegates would pick Obama for prez; unwilling to ignore Clinton's strength and supporters, they would insist that he select her as his running mate in return. This is a possibility, not a prediction. But Clinton has already indicated that she's open, in theory, to a joint ticket, and the longer she's competitive--see Texas and Ohio--the harder she is to dismiss (even if she can't technically catch up). If Obama is feeling magnanimous, the offer could even come before the convention.

Is this rank speculation? Sure. But speculation is what happens to hacks like me when there's seven weeks until the next big* contest. 

Let the arguments begin... 

UPDATE, 1:15 p.m.: Ambinder sketches out an Obama-Clinton administration. Smart stuff:

Obama, by the admissible evidence of his own career, is not an executive. A Vice President Clinton would be a prime minister, tending to Congress and health care reform and trade agreements while Obama travels and inspires and thinks. She would tarnish none of Obama's luster; the qualities he embodies — [qualities] that make him so attractive to Democrats here and, well, in the rest of the world — would be undiminished by the brass-balls first minister he chooses to get things done.

UPDATE II, March 6: For all the commenters who think I'm crazy to speculate about an Obama-Clinton ticket, take note: the vastly more experienced Jon Alter has my back, citing history as his guide. To wit:

Let's say that Clinton supporters are feeling embittered and inclined to sit on their hands. It's not too hard to imagine prominent superdelegates asking Obama to consider putting Hillary on the ticket. This might be the wrong move for him. A national security choice like Sen. Jim Webb, former Sen. Sam Nunn or retired Gen. Anthony Zinni could make more sense. But if Obama did ask Clinton, don't assume she would say no just because she has, well, already served as de facto vice president for eight years under her husband. (Sorry, Al). In fact, she would probably say yes. When there's a good chance to win, almost no one has ever said no. (Colin Powell is the exception). In 1960, when the vice-presidency was worth a lot less, Senate Majority Leader Lyndon Johnson gave up his powerful position to run with John F. Kennedy. 

Read his entire account of how the math makes it nearly impossible for Clinton to win here. 

*Can't forget Wyoming and Mississippi...