The night, according to the instant reaction, belonged to Mitt Romney, after an assured performance in his first face off against Barack Obama. Has the president blown it?
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It was the night Mitt Romney got his groove back. Assured, confident, relaxed, those months of intensive preparation appeared to have paid off. This was, all the pundits agreed, a crucial moment for the Republican challenger: he not only had to hold his own against Obama, but score a decisive win.
In the event, it was Obama who seemed weary and under-prepared, almost uncomfortable to be on stage at all. There was none of the passion which characterises his stump speeches; although there were no disasters, his performance was long-winded, even stumbling.
He failed to mention any of the key planks of attack which the Democrats have deployed during the campaign so far: there was nothing about Bain capital, nothing about that 47 per cent speech.
Was this deliberate? If so, it seemed a missed opportunity, although campaign spokeswoman Jen Psaki defended the tactic: "The president wasn't looking at a checklist of attack lines. He was trying to explain his plans."
Romney's centrist pitch
Romney, however, appeared to have a clear strategy. Never mind the conservatives, appeal to the centre ground, in keeping with the new, more compassionate image which he's been trying to portray, and above all, trying to link the president to the state of the economy.
"The president has a view very similar to the one he had when he ran for office four years ago, that spending more, taxing more, regulating more, if you will, trickle down government would work. That's not the right answer for America," he said.
There was an argument over Romney's tax plans, as Obama accused him of failing to prove how he would fund his projected tax cuts. "If you're lowering the rates as you describe, governor, it's not possible to come up with enough deductions and loopholes that only affect high income individuals or burdening the middle class."
Romney hit back, accusing Obama of flat-out misrepresenting his plan. "There will be no tax cut that adds to the deficit," he insisted. And he got in one of those zingers he's apparently been rehearsing for months: "You're entitled to your own house and your own airplane, but not your own facts."
There were, however, precious few flashes of real humour, save for the moment when Romney apologised to host Jim Lehrer for sticking with his promise to cut funding to the public television network PBS.
"I'm sorry, Jim. I'm gonna stop the subsidy to PBS... I like PBS, I like Big Bird, I actually like you too," he said. Seconds later, the Sesame Street character began trending bigtime on social media: mentions of Big Bird on Facebook soared by 800,000 per cent, while a host of Big Bird accounts suddenly popped up on Twitter.
Putting on the spin
In the spin room, there were certainly no smiles from Democratic strategists, who seemed floored by a host of questions from reporters, David Plouffe insisting "We don't believe in decisive moments", while David Axelrod admitted Romney might get a bump of between one and three per cent, conceding that Romney is "very good on the attack, that's his forte".
The Republicans, on the other hand, were enjoying their moment. "We're feeling better tonight!" grinned Florida senator Marco Rubio, while South Dakota senator John Thune was delighted by the reprieve. "This was a make or break moment for the Romney campaign, and he delivered."
In the plethora of instant polls carried out moments after the debate itself, the voters seemed to agree. CNN's survey named Romney the winner by a margin of almost three to one, while CBS found more than half of those who responded thought Romney had come off best. Another poll of undecided voters showed they were also impressed by the Republican challenger.
According to the online prediction site Intrade, Obama's chances of re-election dropped eight points overnight, although there's no sign yet of any effect on the actual polls.
According to the polling expert Nate Silver, in his FiveThirtyEight blog for the New York Times, even if there isn't much evidence of a long-term impact, the debate could only be good news for Romney. "His comeback chances have improved by a material amount."
The news cycle will certainly be busy over the next few days: tomorrow sees the last jobs report before the election: there's a vice-presidential debate next week, followed by two more encounters between Obama and Romney on 16 and 22 October 16th.
Romney's campaign chief Stuart Stevens was ebullient about the president's knockback: "I don't believe he had a bad debate, he had a bad four years."
Obama put it a different way, on stage last night. "Four years ago, I said that I'm not a perfect man and I wouldn't be a perfect president. And that's probably a promise that Governor Romney thinks I've kept."
Two more debates, five more weeks to go. Round one to Romney, certainly, but there's a long way to victory yet.
Felicity Spector writes about US politics for Channel 4 News