Wednesday’s presidential debate was a tale of four candidates: the two men who stood onstage for 90 minutes and the two rivals Americans have seen for months on the campaign trail and in television commercials. There was no comparison.

Start with President Obama, who may have lost the exchange in as lopsided a manner as any incumbent in recent times. Others have stumbled in the first debates of their reelection campaigns. Ronald Reagan in 1984 and George W. Bush in 2004 come to mind. Both had bad moments that cost them their debates.

Obama didn’t lose because he had a few bad moments. Challenger Mitt Romney dictated the tone and the tempo of the evening, at times acting as candidate and moderator. The president fell behind in the opening minutes and never really found his footing. He lacked energy stylistically and he lacked crispness substantively. He sounded like he does in his news conferences: at times discursive and often giving answers that were longer than necessary.

This wasn’t the Obama seen in his campaign commercials or in the daily scrum with Romney’s operation. His team has waged an extraordinarily aggressive effort from the moment Romney wrapped up the Republican nomination.

Given his vulnerability over the state of the economy, Obama and his advisers sought to define Romney before Romney could define himself. It seemed to work. The campaign attacked the Republican for his work at Bain Capital, for not immediately releasing his tax returns, for putting money in a Swiss bank account and in the Cayman Islands.

Obama mentioned none of that Wednesday. It was as though he left his best attack lines in a folder backstage. Inexplicably, he never mentioned Romney’s recently unearthed “47 percent” comment — his line that nearly half of all Americans pay no federal income taxes, that they consider themselves victims, that they’re dependent on government and that they’re unwilling to take control of their lives.

If those issues weren’t worth mentioning during the debate, why has Obama’s campaign spent the past four months and hundreds of millions of dollars driving home that message? Perhaps his advisers think they’ve done all the damage they need do with those attacks. There is evidence that they’ve stuck. Perhaps the president did not want to project a persona that conflicts with the candidate who captivated the country with a message of hope and inspiration four years ago.

Whatever the case, his performance left Democrats wondering what happened. As one strategist put it in an e-mail message Thursday morning, “ughhh.”

Tad Devine, another strategist who was a senior adviser to Democratic nominee John F. Kerry in 2004, sent an e-mail with this assessment of the president’s apparent strategy Wednesday: “I assume they had a strategy not to engage or get too personal. He was like he had been in many previous debates, but in these very different times, cool and calm is not as powerful as it once was. They have to recalibrate or risk being pushed aside by the new and improved Romney.”

Romney, too, seemed disconnected from the candidate Americans have seen over the past year. On the campaign trail, he is awkward. He is corny and wonky. His stump speeches neither soar nor strike home with real force. Only in debates did he shine during the primaries ,and on Wednesday he was back on comfortable ground. He knew his brief and he seemed happy to deliver it face to face with the president.

Romney did what he wasn’t fully able to do at the Republican National Convention, which was to make the debate as much about Obama’s record as possible while giving viewers a better sense of what he would do to get the economy moving.

But who was the Romney Americans saw on Wednesday? This was not the candidate who lurched to the right to win the GOP nod. This was not the nominee of a Republican Party that is more conservative than it was when conservative icon Reagan was president. This was moderate Mitt from Massachusetts, the turnaround artist with a plan to fix the economy.

As William A. Galston of the Brookings Institution put it in a post-election analysis, “Romney presented himself as a reasonable man — neither an extremist nor an ideologue. He calmly rebutted familiar attacks on his proposals. He was clear and forceful, tough but respectful.”

But in the aftermath of the debate, Romney will face plenty of questions about his agenda, including the one that the president never asked on Wednesday. Romney insisted repeatedly that he does not have a $5 trillion tax-cut plan that would favor the wealthy, although independent analysts have said it would.

If that’s not his plan, what is? How much would it cost? And how would he make the math add up? He rebutted Obama’s criticism by deflection, not by engagement. He still hasn’t said what loopholes and tax expenditures and deductions he would get rid of.

In the hours after the debate, Obama campaign advisers insisted that they would tear into Romney for what he said and didn’t say. The president did not make his criticism stick in person. He’ll have two more chances to do so in upcoming debates. But the next opportunity will be Vice President Biden’s, when he debates GOP vice presidential nominee Paul Ryan on Thursday in Kentucky. It’s unlikely he’ll leave the 47-percent issue backstage.

Both sides believe that the contrasts drawn on Wednesday favor their candidates. Obama’s team says Romney is on the wrong side of public opinion on Medicare, on dealing with the deficit and on protecting the middle class. The Republican’s team argues that Obama is on the wrong side of public opinion in calling for higher taxes, more spending and more regulation. Obama called Romney’s economic plan trickle-down; Romney said Obama’s plan is “trickle-down government.”

Republicans were elated by what happened Wednesday. They knew that a bad performance by Romney might have all but doomed his chances of winning the election. Now they see a race joined again. Stuart Stevens, the campaign’s chief strategist and a target of considerable criticism over the past month, looked particularly pleased as he fielded questions from reporters after the debate.

Stevens has argued for months that Obama not taking ownership of his record would be his biggest obstacle to reelection. He said the debate proved that. “I don’t think [Obama] had a particularly bad debate,” he said. “He has a bad record.”

Stevens said polls show a virtual tie nationally and noted that challengers often don’t overtake an incumbent until the very end of the campaign. Obama advisers stressed that Romney still has a narrow path through the battleground states to win the 270 electoral votes he needs and they seemed determined to make that part of whatever narrative comes out of Wednesday’s exchange.

Democrats were sobered by how the president did during the debate but think that fundamentals still work in his favor. Stan Greenberg, a Democratic pollster, said Romney’s victory was “convincing, but hardly changed the race.” He said that the Republican’s performance probably would win over some GOP-leaning independents who had been wavering or tilted toward Obama, but that underlying forces will help the president.

“That said,” he added, “I think the president will have to be much more passionate about the changes he will bring, and bolder. In our dial tests, his best scores were right at the beginning when he laid out four things he would do. People are still looking for what the candidates will do. Obama will have to show much more.”

Devine said the effect of the debate is taking away Democrats’ hope that Obama might score a big victory in November and help other party members in down-ballot races. “That huge opening may now be lost if Romney makes up ground or, even worse, if it looks like he will win,” he said. “People want progress and to turn the page after 11 years of doubt, and last night Romney looked more like the guy who could and would turn that page for them.”

Said Steve Rosenthal, a Democratic strategist with ties to organized labor: “Romney is a top-notch debater and the president had an off night. Debates are like speed bumps — you have to slow down to get past them but then you can resume your normal cruising speed. The public is evenly divided, and this is going to be a race to the end. Now it’s onto the next [debate], but hopefully last night was a wake-up call to anybody on our side who had grown overconfident or complacent.”

It will take days for the impact of the exchange to filter through the electorate. Only then will it become clear whether or how much it changed things. Romney far exceeded expectations, and for now that has made this a different contest.

For previous columns by Dan Balz, go to