Oh the blissful brevity of it all. Yes, even if Gordon Brown has lost, the removal van may not be turning up this afternoon at the back door of Downing Street to cart off his personal effects. But was it really only four weeks ago that Gordon Brown went to see the Queen – and only three since the first leaders' debate which turned the campaign on its head? Here in the land of the perpetual campaign, four weeks doesn't even cover the warm-up for the Iowa caucuses.
But neither brevity, nor the startling ascent of the Liberal Democrats, explains why the Americans have been so interested in our election of 2010 – to some degree repaying the compliment of 2008, when the US held an election that transfixed Britain (and most of the rest of the world).
For Obama, read Clegg, another outsider who defied the conventional wisdom. For our fascination with the issue of race in the US, read the fascination here with class in Britain. Two years ago, we were dissecting the possibility of the first black president. For the last month, Americans have been treated to dissertations on the word "posh," and of what it means that, for the first time in half a century, the next prime minister might be an Old Etonian.
But there's a more important reason too. In fact the most gripping American election of recent times – and the one that most resembles the campaign that's just wrapped up in Britain – was not 2008. It was 1992. That too featured its bright new thing, in the person of Bill Clinton who revitalised the Democratic party, much as Clegg and David Cameron have done for their parties.
Even more pertinently, it featured in Ross Perot the strongest third party candidate in a US election since 1912, when Teddy Roosevelt formed his Bull Moose Party. 1992 was a heck of an election. As in Britain in 2010, the campaign suddenly became a voyage into uncharted waters. At one point Perot, a Texas businessman with a squeaky voice, paranoid disposition and bottomless pockets, actually led both Clinton and the incumbent George H W Bush.
For a moment then, as in Britain now, the two-party system appeared genuinely at risk. For once, pundits had to admit they had no more idea what would happen than the average punter. "Political Chaos in Britain," ran the headline in the San Francisco Chronicle this week. It sounds frightening, but the wonderful thing about electoral chaos is that for once the voters, not the backroom strategists, pull the strings.
So it was in 1992. Perot left the race in a tantrum that July, accusing the Bush campaign of plotting to sabotage his daughter's wedding (yes, really). But five weeks before election day, he re-entered the contest. By then, his mental stability was being seriously questioned. Even so he won almost 20 per cent of the popular vote.
Alas, the American winner-take-all system is even rougher on third parties than our first-past-the-post. Perot's support was spread evenly across the country, and he didn't win a single one of the 538 electoral college votes. What he did do was guarantee the victory of Bill Clinton.
If the polls are correct, Nick Clegg will wake up today as Britain's political kingmaker, and thus final arbiter of Gordon Brown's removal date. In that sense too, "chaos" is a thoroughly uplifting concept, reflecting how the inequities, the distortions, the sheer out-datedness of our electoral system have finally almost caught up with it.
"Almost", I say, because we still don't have fixed-term Parliaments. Until we do, the man who gets his foot in the door of No 10 will be able to call a snap election when he thinks his party can win an outright majority of Commons seats on its own, removing the need for tiresome negotiations with his junior partner on electoral reform.
To attain a fairer system in Britain, we therefore need not just one hung parliament, but a whole string of them. America hasn't reached this point yet, but it's getting there – which is another reason why political experts are watching what happens in Britain so closely. In both countries, acute economic problems could be the catalyst for fundamental political change.
If anything, Britain's problems are even greater than those of the US: witness the reported and thus far undenied remark to an American visitor by the Bank of England governor, Mervyn King, to the effect that "whoever wins this election will be out of power for a whole generation, because of how tough the fiscal austerity will have to be".
But the US social and economic boat is only marginally more sea-worthy. As in Britain, recession and rising unemployment have sharpened the immigration debate. More than in Britain, they are pushing politics to the right; the swing to the Republicans in the upcoming mid-term elections is likely to exceed what the Conservatives achieved yesterday. But victory in November will mean Republicans bear a share of responsibility for action to reduce a federal deficit running at over 10 per cent of GDP, a proportion close to ours, and equally unsustainable. If a Republican defeats Obama in 2012, the party will have the entire responsibility.
And even more blatantly than in Britain, politics do not reflect what the public wants. It detests the petty hyper-partisanship of Congress. The stridency of the far right obscures the fact that the largest political grouping in the US is not the Democratic party or the Republican party, but people who identify themselves as independents.
In Britain, that space in the decisive centre is increasingly occupied by the Liberal Democrats. For the time being, America's more rigid system means that independents must flit from one major party to the other, determining which of them wins the election. But this state of affairs is not eternal.
In 1992, the US economy was much stronger, and the deficit far smaller, than today, and by no stretch of anyone's imagination could Ross Perot be described as "Mr Charisma". Nevertheless, he won a fifth of the popular vote. If Nick Clegg can redraw Britain's political landscape today, the likelihood only grows that someone will redraw America's tomorrow.