This is not completely over. The margin of error is comfortably wide enough in the six or seven swing states. I would be less surprised by a Romney short-head victory than I was when Britain looked itself in the shaving/make-up mirror in 1992 and decided that, whatever their shortcomings, John Major's Tories were a better idea than that bottomless pit of vacuous Valley-Welsh socialist rhetoric, Neil Kinnock. What a terrific morning the next day! BBC and Guardianista types weeping openly, blaming the polls and the Sun and the Mail and the weather and the TV schedules and trying to come up with a conspiracy theory. Pity that Major then governed quite so hopelessly, but I suppose he did the country a favour by forcing Old Labour into permanent retirement.
In short, Kinnock was found out during his campaign in such a way that the electorate decided not to trust him with the job. Obama was up against a hopeless old candidate four years ago, was trusted with the job, but has been found out over four long years.
If 4 things happen, Romney wins:
Obama's 2008 high-water-mark vote shrinks by a modest amount (3 in 100, say) as his HopeyChange mantra now looks as dated as a Mark 1 iPod;
Those tepid Republicans shamed by the Dubya second-term and uninspired by McCain in 2008 return to the Romney candidacy (again, let's say a modest 20% of 'lapsed' Republicans in 2008);
The polls overstate Obama by 1 in 200, or 0.5%, for the usual reasons: Republican-vote admission shame, incumbent bias.
Floating voters break for Romney on the day, 55-45. Psephologists agree that this usually happens when the incumbent has been, by common consent, a first-term underperformer, and the challenger has 'won' the campaign by improving in the polls, even only modestly.
Of course, these 4 things have to happen in the swing states, rather than Nebraska or Mississippi, but I think they are all more than likely. The 1992 UK exit-poll debacle was blamed on a late swing to the Tories, which I don't believe - Kinnock hadn't sealed the deal in 1992 any more than the hugely disappointing Obama has done with this election.
UPDATE: Wednesday 1030
No real winners emerged last night. Obama, without an agenda and therefore without much of a mandate, also has a Republican House to obstruct his more fanciful welfare-state ambitions. Maybe they will prevent Obama2 from increasing the debt as much as Obama1 - if they don't the Dollar is sunk.
Romney was neither fish nor fowl by the end. A chap writing in the Independent this morning suggested that the message of the election was that America still has a reasonable appetite for moderate conservatism, but the Republican Party didn't want to provide the candidate. I think Romney did quite well, but frankly he should have been pushing on an open door, given a poor incumbent president and a bad economy.
I forecast that Obama will play a LOT more golf in the next four years.