WASHINGTON -- When Barack Obama entered the debate hall at the University of Denver Wednesday night, the air was clear and warm. When he left, the winds where whipping and the temperature had dropped 20 degrees. Coincidentally, that was also the same number of undecided voters who thought the president had a good debate.
In two different polls of undecided voters by CNN and CBS, Obama received grim reviews. In the CBS poll, 46 percent thought Romney had done the better job. Only 22 percent thought Obama prevailed. In the CNN poll, 67 percent thought Romney had performed well. Only 25 percent could say the same of Obama. In another poll conducted with a group of "Wal-Mart Moms" in Las Vegas, Romney also scored high. His image climbed 20 points, while Obama's moved just 5. Many of the women had "somewhat tuned out Mitt Romney," according to the findings reported by a bipartisan polling team. "After seeing him this evening several are now re-engaged and want to learn more about him. They were somewhat disappointed with President Obama's performance. They do not believe he made the case for how another four years will be different or better."
Instant polls are a small sample and they only take a momentary impression, but that's all the Romney camp needed. Going into the debate Romney was on the long end of three bad weeks. Romney's advisers were looking simply for a pause in the race - a moment for voters to take a second look at Romney. They got it Wednesday night.
Romney had two tasks. He had to explain why the president was a failure while also seeming appealing enough for voters to think he might have policies that will succeed. The risk was that he would get the mix wrong. He'd come off as too aggressive and turn people off. Romney was certainly aggressive. "You've had four years, " he told the president during the discussion of deficit reduction. "You said you'd cut the deficit in half. It's now four years later. We still have trillion-dollar deficits. You found $4 trillion to reduce or to get closer to a balanced budget, except we still show trillion-dollar deficits every year. That doesn't get the job done."
Romney seemed alive to the challenge, almost like he was enjoying himself. He looked in command, like he belonged on stage with the president. Voters polled by CBS after the debate showed a dramatic increase in the number who thought Romney cared about them. Before the debate, only 30 percent said they thought Romney "cares about your needs and problems." After the debate, 63 percent believed he was more empathetic of others.
It was clear from the start of the debate that Romney was going for kinder and gentler. He spoke of two different voters he'd run into who were struggling in the economy. "I was in Dayton, Ohio, and a woman grabbed my arm, and she said, 'I've been out of work since May. Can you help me?' Ann yesterday was at a rally in Denver, and a woman came up to her with a baby in her arms and said, 'Ann, my husband has had four jobs in three years, part-time jobs. He's lost his most recent job, and we've now just lost our home. Can you help us?' And the answer is yes, we can help, but it's going to take a different path."
The president's numbers also improved among those voters polled by CBS on the question of caring. He started with 53 percent, and by the end of the night, 69 percent said they thought Obama cared about them. It was the only bright spot of the night for Obama, who otherwise seemed listless and detached. When Romney spoke, Obama looked down at his notes and smiled, which conveyed something between low-stakes bemusement and "I can't believe I have to listen to this guy." Perhaps that's what happens when you're president and people don't often tell you that you're wrong.
In debates over Romney's tax plan, health care and Medicare, Obama didn't prosecute his case nearly as powerfully as his opponent. At times the president seemed to think merely by appealing to voters' deductive reasoning he'd make his point. "Does anybody out there think that the big problem we had is that there was too much oversight and regulation of Wall Street? Because if you do, then Governor Romney is your candidate." That's a circuitous way to make a rather simple point. Obama did that again and again.
The president seemed thrown off by the fact that Mitt Romney was far more like the man who won the governorship in Massachusetts than the one who had won the Republican primary. In a debate about tax cuts, Romney consistently denied that his tax cuts would total $5 trillion. Shouldn't Republicans boast about cutting taxes? What Romney meant is that his 20 percent across the board cut would be revenue neutral and not increase the deficit. That doesn't mean, however, that they won't also be large tax cuts.
Romney also seemed to moderate his tone on regulations, particularly Dodd-Frank. Previously, his criticism of the bill had been much harsher, but in Denver on Wednesday night he seemed to say that it's big problem wasn't so much the regulations but the fact that the regulations were unclear.
Romney bragged about his Massachusetts health care plan, his ability to work with Democrats, accused Obama of giving a "kiss to New York banks," and insisted that he wouldn't cut taxes on the rich. "I'm not looking to cut massive taxes and to reduce the - the revenues going to the government," Romney said, sounding unlike the self-described "severe conservative" of the previous 18 months. There might have been a time when this would have upset conservatives, but as GOP strategist Michael Murphy put it, conservatives "have tasted losing for the last couple of weeks." They're not going to complain now after a night that "tastes like winning."
This was Mitt Romney's best night of the campaign. Now he has to sustain it. In the past, debates haven't stuck with voters for long. There wasn't one Romney moment that voters could take home and replay at work the next day. Romney seemed competent and in command, but how does that get passed around to other voters? Perhaps it's enough that many voters who were looking at him for the first time didn't see an indifferent millionaire. But his reputation for ideological malleability may help the Obama team argue that Romney is reinventing himself again. That will probably mean a pretty brutal round of charges about his ability to tell the truth. As the campaign heads deeper into October, the president is going to have to regroup, shake off the chill, and turn up the heat.
Dickerson is Slate's chief political correspondent.