By MICHAEL D. SHEAR
For weeks in August and September, while conservative pundits increasingly began writing off Mitt Romney‘s campaign as hapless and hopeless, top aides to the Republican presidential hopeful privately preached patience and resolve.
“Romney took a hit,†a top adviser to Mr. Romney conceded in late September, after Mr. Romney's poll numbers fell in the wake of his comment about how “47 percent†of Americans were dependent on government and saw themselves as victims.
“But nothing that a candidate has said in September has ever determined a race unless it was ‘your honor, I plead guilty,'†the adviser said, waving aside those who declared the race over. “It's O.K. to think for yourself. Resist the urge to follow.â€
Mr. Romney's debate performance last Wednesday was just the kind of moment that his advisers were waiting and hoping for: a single event that quickly erased the gloom and doom surround ing his White House bid and provided new momentum for his campaign.
In rallies over the weekend, Mr. Romney has been a different candidate. His voice seems stronger, more confident. His advisers and surrogates are happier and less defensive. And his supporters are telling pollsters that they are finally proud to support his candidacy.
A new Pew Research poll released Monday found that Mr. Romney's supporters are more engaged and more enthusiastic about their candidate than they have ever been during this election season. That appears to have translated into a narrowing race, with several polls showing President Obama‘s national lead shrinking in the wake of the debate.
Now, with 28 days and three more debates left, Mr. Romney and his advisers have to worry about another quick turnaround - this time in Mr. Obama's direction.
The sizable shift toward Mr. Romney after the first debate is a perfect example of the unpredicta ble role that momentum plays in American presidential campaigns.
In 1980, George H.W. Bush claimed to have “the Big Mo†after defeating Ronald Reagan in the Iowa caucuses. “What we will have is momentum,†Mr. Bush told CBS's Bob Schieffer that morning. “We will look forward to Big Mo being on our side, as they say in athletics.â€
Since then, academic researchers have documented the tendency for presidential hopefuls to surge forward on the strength of single events, buoyed by a sudden infusion of confidence, money and public support.
It was just that kind of momentum that seemed to be carrying Mr. Obama toward a re-election victory in the late summer and early fall this year.
A series of mistakes and missteps by Mr. Romney's campaign and an aggressive advertising effort by the Democrats had gotten the ball rolling for Mr. Obama. Polls in September all showed him gaining nationally and in all of the important battleground states. The carping among conservatives had begun with Peggy Noonan, a former speechwriter for Mr. Reagan, calling his campaign “incompetent†and a “rolling calamity.â€
That all ended abruptly on Wednesday, when Mr. Obama's lackluster debate performance served as a surprising contrast to the aggressive, energetic and somewhat more politically moderate version of Mr. Romney who showed up in Denver.
By the end of the debate momentum had clearly shifted, as evidenced by the faces of the advisers to both candidates: Mr. Romney's aides were as ecstatic as Mr. Obama's were depressed.
Such moments are sometimes fleeting, as Mr. Bush discovered in 1980 (and other winners in Iowa and New Hampshire have found out). The momentum behind Mr. Bush quickly evaporated and Mr. Reagan went on to defeat his rival for the Republican nomination that year.
For Mr. Romney, the danger is that his newfound popularity does not necessarily reflect a fundamental altering of the dynamics of the race against Mr. Obama. A 90-minute debate - even one watched by 70 million people - does not change the Obama campaign's field operations in swing states or take away the trappings of the presidency that Mr. Obama enjoys.
And there remain at least three more opportunities for Mr. Obama's team to return the favor, seizing momentum back from his Republican rival as quickly as they lost it.
The first chance comes on Thursday, when Vice President Joseph R. Biden Jr. faces Mr. Romney's running mate, Representative Paul D. Ryan of Wisconsin, for their only debate.
Vice-presidential debates are often inconsequential, but Mr. Biden has an opportunity to remedy Mr. Obama's lack of interest with his typical, over-the-top intensity. If Mr. Biden can avoid making any gaffes - or if Mr. Ryan seems ill-prepared - momentum could shift.
But the biggest moments ahead are the two remaining presidential face-offs. The next one will be a town-hall-style debate betwe en Mr. Romney and Mr. Obama on Oct. 16. The last debate, which will focus on foreign policy, will be on Oct. 22.
Mr. Obama's aides have already signaled that the president intends to be much more aggressive in the next debate. David Axelrod, the president's chief campaign strategist, told reporters that Mr. Obama will approach the final two debates with the idea that he “can't allow someone to stand there and manhandle the truth.â€
In the wake of the debate, Mr. Obama's team has gone on the attack, accusing Mr. Romney of lying during the debate about his real record. The point of the attacks? To slow down Mr. Romney's momentum.
The president got some help from the monthly jobs numbers two days after the debate. The surprise drop in the unemployment rate, from 8.1 percent to 7.8 percent, provided a new and better story line for Mr. Obama just when he needed it.
But the recent polling shows clear movement in Mr. Romney's direction. The question now i s whether he can sustain that momentum for another 28 days - or whether Mr. Obama can steal it back.
