Realistically, very few presidential debates have the kind of clear-cut winner that the first Romney-Obama debate did. It's more productive to look at what each candidate came looking to accomplish.
Romney: Romney came in tonight with three main goals.
One, he wanted to repeat his strong showing from the first debate. He did that - he was vigorous, authoritative, and came across as the same technocratic moderate that he really is.
Two, he wanted to avoid any major gaffes that would foul up the momentum he has going. He did that, too. He never seemed stymied, never really put his foot in his mouth in a harmful way. Even when he bought into the false left-wing premise of a question on gender pay equity, he came away talking about his own experience hiring women in his cabinet (he might have mentioned his female running mate in Massachusetts as well).
Three, he wanted to go in for the kill. On that, Romney failed. He let Obama get away with some flagrant lies, like claiming that Planned Parenthood performs mammograms. He completely botched an obvious attack on Obama's disastrous and dishonest response on Libya, to the point where even moderator Candy Crowley - who was mostly running interference for Obama on this and on Fast & Furious - had to step in and remind Romney that Obama's Administration had been dishonest on Libya. Romney forced a confrontation on the facts on oil drilling - one the fact-checkers have to give him - but like John McCain in 2008, he seemed hesitant to really take the fight to Obama on more divisive issues.
It's true that Obama is now set up to be completely dismantled on Libya in the third debate, if Romney comes loaded for bear. But I suspect that by the time that debate arrives, nobody will be left undecided.
Obama: Obama also came in with goals, four of them.
First, Obama needed to show that he actually still wants the job. He did that - he was much more vigorous tonight, showing some fight and some indignation and squaring off in some true alpha-dog battles with Romney.
Second, Obama needed to give his partisans something to cheer for. He was late sometimes in doing so (especially waiting for his closing to attack Romney on the 47% tape) but did deliver.
Third, Obama needed to lay out something more like a positive second-term agenda. On this, he failed miserably. He has nothing to offer but a stew of "more of the same." Closing with the 47% attack really underlines the extent to which this is a campaign bereft of positive promise.
Fourth, and perhaps most important, Obama needed to strip the bark off Romney, convince the voters that he was in no way an acceptable alternative. And outside the choir, Obama really didn't seem to do that. He didn't dismantle Romney's agenda, he just disagreed with it. He basically denied the existence of the problems Romney cited on energy policy. Despite pre-debate preening on Romney's record in Massachusetts, Obama never attacked that record. And despite his heavy reliance to date on attacking Romney as a tax-hiker, Obama spent far more of the debate bashing tax cuts, leaving little doubt which candidate was the low-tax candidate.
Romney's strongest moments were two. One, he just buried Obama in response to an African-American man who declared himself a disheartened Obama '08 voter; Romney responded with a blistering indictment of Obama's economic record. And two, he offered a great answer on American competitiveness. He also came away with a good answer on immigration, albeit one that won't please many of his own primary supporters.
One more point: I think Romney did a much better job of remembering, as the debate wore on, that an audience of Long Islanders was not the real audience. Obama's attack on the NRA in particular is unlikely to play well in key swing states.