If Noam Scheiber’s analysis is right, in the 5 days between the Iowa caucuses and the New Hampshire primary either Hillary Clinton will become the presumptive Democratic nominee or Barack Obama will. His argument is that Obama could not recover from a clear victory in Iowa by John Edwards. The 2007 campaign could tolerate several alternatives to Hillary Clinton, but once the voting starts on the third day of 2008 that throng will very quickly be winnowed to one. If that one is Edwards, however, he will be ground down in New Hampshire and beyond by the huge disparity between Clinton’s bank balance and his own. So a Clinton victory is a Clinton victory, especially if Obama finishes third, but an Edwards victory is also a Clinton victory.

An Obama victory in Iowa would be an Obama victory, not just in the limited and immediate sense, but also because the only way Edwards can survive is by winning there. By depriving him of that victory, Obama reduces the race to a contest between himself and Hillary Clinton. Obama, unlike Edwards, does have enough money to compete against Clinton until the race is settled. More importantly, after Hillary’s 15 years as a national figure, the majority of Democrats around the country who list Edwards (or Joe Biden or Chris Dodd or Bill Richardson) as their first choice are likely to gravitate to Obama, not her. That is, there are a lot more Democrats who harbor deep misgivings about Hillary than about Obama; a post-Iowa Clinton-Obama contest would be Obama’s to lose.

There’s a fourth possibility, in which a Clinton victory in Iowa would be an Obama victory. That would require Obama to finish a close second to Clinton, with Edwards a disqualifying third. Though Obama leaves Iowa as the loser to Clinton, he does leave Iowa in a one-on-one race against Clinton, with his campaign treasury intact and with a bigger upside than Clinton in New Hampshire and every subsequent primary. “An inconclusive muddle actually benefits Obama,” Scheiber argues, because “without Edwards in the race, Obama consolidates the anti-Hillary vote, which nudges him over the top in what’s now a dead-even race in New Hampshire, makes things look pretty good for him in South Carolina (where he’s been closing but still has to convince some African-Americans he can win), and generally gives him the upper hand for the nomination.”

That argument leaves the question of what constitutes a narrow victory by Clinton over Obama in Iowa. Scheiber guesses that if “Hillary wins by more than a point or two, [then] the race is basically over.” Conversely, a one- or two-point victory by Clinton over Obama leaves the race an “inconclusive muddle.”

Perhaps, however, the mainstream media won’t tolerate an inconclusive muddle. America’s most powerful writers and editors are not famous for diffidently saying, “Far be it from us to impose a master narrative on the ambiguous and confusing jumble of facts before us. Rather than arrogantly and fatuously rushing to say ‘what it all means’ when no one can possibly know, let’s withhold our interpretations until more voters in more states have spoken, and only then offer our opinions about front-runners and also-rans.”

It’s entirely possible, then, that even a photo-finish Clinton victory over Obama will mean the race is basically over. After weeks of mostly bad press and sinking polls, she would be this year’s “Comeback Kid” by doing “better than expected.” (Her husband, after all, got to be 1992’s Comeback Kid by finishing second in New Hampshire to Sen. Paul Tsongas; the numerous reasons to think that Tsongas’ victory was more impressive than Bill Clinton’s silver medal didn’t matter.) Five days of good media would seal a victory for Hillary in New Hampshire, and the brief holiday from inevitability would be over.

The mainstream media is supposed to be much weaker in 2008 than it was in 1992, when there was no blogosphere, barely an Internet, no Fox News or MSNBC, etc. Its ability to forge a master narrative has been permanently subverted. Perhaps. But front-loading the primaries was supposed to diminish the role of Iowa and New Hampshire in the nominating process, yet so far has only enhanced their importance. The fact that the herd of opinion makers is much bigger now than it was 16 years ago may mean only that the herd mentality is more powerful now than it was then, and the 2008 stampede will be quicker and more decisive than 1992’s.

2008 will be the first election since 1952 in which neither a sitting president nor a sitting vice president is running for the presidency. A large majority of the electorate has no recollection of a race in which both parties’ nominations are seriously contested. There could be surprises and ambiguities in both parties. A final question that will emerge in the 48 hours after the caucuses conclude is whether the media has the power to shape two ambiguous results into one master narrative. If it does, then there will be only one big story coming out of Iowa. Does a Mitt Romney victory make him the Comback Kid, diminishing a Clinton victory and making an inconclusive muddle for the Democrats possible after all? Does a Mike Huckabee victory constitute big news or old news, making him the Paul Tsongas of 2008 for meeting expectations that he was unfortunate enough to raise a news cycle too early, rather than late enough for his victory to be “dramatic”? Never has the advice, “Stay tuned,” been more appropriate.