And here we go again. Tomorrow's Democratic primaries in North Carolina and Indiana might yield a conclusive result that will finally wind this exhausting and enervating battle towards a conclusion.
But the greater likelihood is that the fight will continue into June (the last contests are June 3). And if it continues into June, it could well last, through fights over superdelegates and what to do about Florida and Michigan, through most or even all of the summer, up to or near the Democratic convention in the last week of August, giving the nominee just eight weeks to mount a general election campaign. That's impossibly brief by American standards, especially when the fellow from the other party, who sewed up his nomination in March, has been given a five-month head start.
For months now, the race has been Barack Obama's to lose. He's had a number of opportunities to end this contest with just one win, and he hasn't been able to do it. Some of this has to do with Hillary Clinton's destructive "kitchen sink" campaign, which began in late February when she was in danger of being chased from the race, and which lately has placed her perilously close to positioning herself in almost rightwing populist terms the better to tag Obama an "elitist".
Some of it has to do with the aggressive vetting of Obama by the media on sometimes dubious questions. And, no doubt, some of it has to do with plain old racism, which has not, wouldn't you know it, disappeared from American life.
But some of it has to do with Obama himself, and his campaign. And if he does end up losing the nomination - I think there's about a 40% chance of it now, though I'm still in the minority among US commentators in thinking it's that high - some of the finger-pointing will have to be aimed at the mirror.
There's been a paradox at the heart of the Obama campaign, and it goes like this. He has been, for millions of voters, a great inspirational leader, with a unique talent for defining the historical moment; but at the same time, in many ways, he hasn't been a very good day-to-day campaigner. Campaigns must have Big Themes, sure. But at ground level they are largely about controlling the daily and weekly grind of issues. "Winning the headlines," it's sometimes called. The campaigns that win are generally those that pull this off.
Now think of the issues - and here I mean actual issues, not lapel pins - that have been front and centre since Clinton started her run in early March. They've included the North American Free Trade Agreement (Nafta); preparedness to be commander-in-chief; the federal gas tax; and, of course, the lamentable Jeremiah Wright, which, distinct from lapel pins, has indeed been a legitimate issue.
On all four, Obama has been back on his heels, answering criticisms. On the first three, the Clinton campaign has completely framed the debate - whether fairly or disingenuously is in the eye of the beholder, but there's no doubt she's been asserting and he's been responding. Wright was pressed more by the media than by Clinton, although she got in her digs, but here too Obama has been playing defence.
Campaigns can't see every bullet coming at them, but there's certainly a case to be made that the Obama campaign could have been quicker on the uptake on all these matters. This is especially so with regard to the issue that is the greatest threat of all - the words of the good reverend.
Interesting hypothetical: suppose Obama had dealt with Wright pre-emptively. It was known back when he announced his candidacy in February 2007 that Wright was going to loom as a problem; after all, Obama disinvited the man from delivering the invocation at his announcement event.
So, suppose some time right around then, or perhaps last summer, before everything was at stake, Obama had said: "You know, you're going to be hearing some quotes from this man, and they're going to fall pretty hard on many people's ears." And had then gone on to explain some of the things he's spent the past month explaining.
I can't say I know this would have worked. It might have scared off donors, it might have put him in a box from which he couldn't have escaped. But I can say this much: I have watched, time and time again, as campaigns knew that X or Y was going to come up and bite them at some point, them just ignoring it, figuring the risk was too great. Obama was asked yesterday by the TV host Tim Russert why he didn't deal with Wright earlier. "When you're in national politics," he replied, "it's always good to pull the Band-Aid off quick ... but life's messy sometimes."
In contrast, the occasional campaign that has confronted its potential problems head-on has usually benefited. This is a special skill of John McCain - liberals complain about the media giving him a free pass, and Lord knows they do, but part of the reason they do is that McCain has been very shrewd about showing journalists his dirty linen before they uncover them on their own.
Obama has already missed the opportunity to be that kind of candidate. Of course, Clinton isn't exactly known for her freewheeling ability to admit error either. But in the past few weeks, she's made fewer of them.