In a frenzied closing day, Barack Obama and Mitt Romney crammed in final visits to key battleground states – the president ending what, win or lose, will be his last campaign in the place where his "improbable journey" began nearly five years ago, in rural, midwestern Iowa. There is little more they can do.
Their fates lie now with the machines they have built on the ground, the efficiency of their get-out-the-vote operations and, of course, with the voters themselves.
The president acknowledged as much when he addressed a rally in the frigid night air of Bristow, Virginia, late on Saturday. "I'm sort of a prop in the campaign," Obama said, conceding that at this late stage organisation is king.
As to who is the more confident of victory, there the battle is less between Obama and Romney than between two political tribes: the priests and the mathematicians.
Those of a scientific bent, who crunch the numbers and regard the uber-analyst and blogger Nate Silver as a secular deity, believe the contest is all but in the bag for the Democrat.
Yes, the national polls may be locked in a statistical tie, but in the decisive states – chief among them Ohio, where Romney will make one more, tradition-defying visit on Tuesday – Obama has held a narrow but consistent lead, one that firmed up during the final weekend.
Experience suggests election eve polls tend to be borne out on the day itself. The mathematicians say Romney's path to 270 electoral college votes has become so convoluted as to be near-impossible.
To win, they argue, he would need to be comfortably ahead in the likes of Virginia and Colorado and he is not. They cite 2004, when incumbent George W Bush was similarly deadlocked in national polls only to beat John Kerry.
They confidently expect Obama to repeat the trick, while one bookmaker, Paddy Power, has already paid out £400,000 to punters who backed the president. Silver gives Obama an 86.3% chance of victory.
The priests however – a fraternity that currently includes many Republicans – insist such certainty is impossible. An election is a human event, with too many variables. They note the polling that says independent voters are breaking for Romney in Ohio, which would usually point to success. They argue that the electorate is not the same as it was in 2008, that there will be fewer young and African-American voters and that that will hurt Obama. They point to specific counties where early voting indicates Democratic turnout down and Republican turnout substantially up.
That's hardly a surprise, say many Democrats, considering what they call "voter suppression" efforts by Republican state officials, closing polling stations and cutting short early voting in heavily Democratic areas. Tellingly, the Obama campaign has 2,500 lawyers on standby in Ohio alone, just in case things get close and ugly.
Most unexpectedly, Republicans have seized on Pennsylvania, which their party has not won since 1988 but where a poll showed Obama's earlier lead wiped out, the two men on 47% each. If Pennsylvania is genuinely wobbling, that would spell disaster for the president.
Publicly, the Obama camp dismissed the poll as rogue and politically tainted. But they took it seriously enough to deploy their biggest gun, sending a hoarse Bill Clinton to do four events in the state on Monday.
Above all, the priesthood points to those intangibles they say the data-analysts miss. Romney is addressing large, enthused rallies which, they believe, do not suggest a candidate heading to defeat. On Friday, the Republican brought out between 20,000 and 30,000 to West Chester, Ohio. This same weekend, an Obama event saw only around 2,000 Ohioans fill a high school gym in Cleveland.
Still, Democrats can cite intangibles of their own. On Saturday night, some 25,000 braved icy temperatures to attend that late night rally in Virginia.
They whooped their delight at seeing two presidents, Clinton and Obama, high-five and hug, memories of the 2008 battle between them safely buried. The eyes of supporters may not have shone with hope and expectation the way they did when Obama addressed an election eve crowd of more than 80,000 in the state four years ago. "But now there's real strong determination to let him finish his work," volunteer Richard Russey, 60, told me. Next to him, Sharon Jenkins, 54, said she was part of a "veritable army" of Obama activists that was bigger than in 2008.
What's intriguing is the absence on both sides of what New York Times columnist Ross Douthat calls the "aura of defeat", defined as a losing campaign's tendency to go negative, hyping up trivial issues to motivate core supporters and seizing on minor slip-ups by the other side. A fortnight ago, Douthat detected that aura around Obama.
But in the final days, there was little sign of it. In Bristow, Obama's closing argument focused firmly on the big picture, even extending to some Martin Luther King style rhetoric. "It's up to you," he told them. "You've got the power. That's why I need you, Virginia. Don't get tired, don't get weary."
Romney too exudes confidence. On Monday he addressed an energetic, flag-waving indoor crowd in Fairfax, Virginia who cheered every time he spoke of "when I'm president," urging them to make the "one final push" that would bring "a new tomorrow."
But there is the odd lurch into that losing mode of behaviour. On Monday Romney was still attacking Obama for suggesting voters should get their "revenge" at the ballot box, a remark Fox News and the Republicans interpreted as a coded call for class war. In fact it was nothing of the sort, but that didn't stop Romney piously insisting that voters be motivated not by revenge, but "love of country".
More important, there have been the first signs of Republicans turning on each other, getting their retaliation in early. Chief among these "precriminations" is the view that Romney failed to reach beyond white America, that their party is too concentrated in the deep south and the great plains.
The mathematicians would say Republicans are right to have that argument now. The priests say they should wait, that elections can surprise you.
Who will win this battle of data against instinct, of head versus gut? Today will settle that – and much else besides.
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image: © Aaron Logan