On the face of it, few political turnarounds have been as astonishing. A mere 14 months ago, a tide of fury at George W Bush and eight failed years of Republican rule swept Barack Obama to power.
Tuesday's stunning loss of a seemingly rock-solid Senate seat in Massachusetts suggests voters' anger is now directed with equal ferocity against Mr Obama and the Democrats. In fact, one crucial element has not changed: Americans' disillusion and exasperation with the way their government works.
Many factors contributed to the came-from-nowhere victory of Scott Brown. He was an excellent candidate; a relative outsider, a natural communicator and infectiously energetic. Maybe too the electorate felt that however hallowed the memory of Ted Kennedy, after almost half a century it was time for real change. "This is the people's seat," Mr Brown declared in his victory speech, not a sinecure to be handed down from one generation of Democrats to another.
The faltering economy, stagnant earnings and a jobless rate of 10 per cent added to the rebellious mood. Another element, unquestionably, was the increasingly unpopular health care measure pushed by Mr Obama and the Democratic majority on Congress, now opposed by a majority of Americans.
Then there's the Obama factor. This was not a referendum on the President, who in November 2008 carried Massachusetts by 26 points. But his approval rating has since slid from 75 per cent to 50 or less. The presidential coat-tails are not what they were. Indeed, Mr Obama's appearance alongside the Democrat candidate Martha Coakley at the weekend may have done as much harm as good.
But one strand links all these reasons, and connects them with the wrath visited by voters on Republicans in 2006 and 2008: the frayed relationship between Americans and their ever-more dysfunctional system of government.
The President's popularity has slipped. But in comparison with Congress, viewed positively by just 25 per cent of the voters, he is adored. And since Democrats control both chambers, they naturally bear the brunt of the blame. Indeed, to judge by recent polls, House Speaker Nancy Pelosi is as unpopular as was Dick Cheney in the waning years of the Bush era.
Nowhere is the resentment greater than among independents, at the fulcrum of US politics, whose support sent Mr Obama to the White House, premised on the belief he would fulfil his campaign promise to change the way Washington – ie government – worked.
It hasn't happened. The climate has grown even more venomously partisan, preventing anything being done. There's the old stench of corruption too. Ms Pelosi promised to clean things up. Instead Americans are offered the unedifying spectacle of New York Congressman Charles Rangel, head of the hugely powerful House Ways and Means committee – the main tax-writing body on Capitol Hill – entangled in ethics and tax avoidance allegations.
Then there are the flaws of the system itself, that can make the US seem ungovernable. The most glaring is the filibuster rule in the Senate (nowhere in the constitution) that allows a minority of 41 senators to block the will of a 59-strong majority. With Brown, the Republicans once more are up to 41.
Another problem is a lack of party discipline, that in the case of the healthcare bill saw Mr Obama and the Democratic leaders literally buying the votes of hold-outs with concessions, proffered behind closed doors, far from public scrutiny. No wonder that out in the country, disgust with Washington grows.
Instead of taking Congress to task, Mr Obama appears ready to indulge its every whim. As his ambitious reform schemes founder – healthcare today, perhaps climate and energy policy and market regulation tomorrow – he seems to have achieved a poisonous combination of big government and no government.
As a result independents are deserting in droves. The trend was already evident in last November's elections where Republicans recaptured the governor's mansion in New Jersey and Virginia, two states Mr Obama had comfortably carried only a year before. The same happened this week in Massachusetts where, although registered Democrats outnumber Republicans three to one, nearly half of all voters are independents.
For the moment Republicans are beneficiaries of this anti-establishment mood, stridently expressed by the Tea Party movement which strongly backed Mr Brown. But Republican incumbents could fall victim to the resentment – a danger he recognised on Tuesday night when he scarcely used the word "Republican". His victory was "all of us against the machine". His was an "independent" majority.
Where this new populism will lead is the most fascinating current question in US politics. It is similar to Poujadism in France in the 1950s in its disgust at elites (in this case Wall Street). But it is a very American movement, of little guys fed up with deficits and with a government that spends like a drunken sailor when they have to watch every cent. If it lasts, the consequences could be momentous.Reuse content