With his historic presidency in peril, Barack Obama will shake off his lethargy with a "strong" and passionate" comeback Tuesday in his second debate with Mitt Romney, a top advisor said.
Obama and Romney meet at Hofstra University, in New York, with the president under intense pressure after the Republican's nimble first debate showing two weeks ago triggered a polling spurt which tightened the race into a dead heat.
The president's team admitted he had a "bad night" in the first debate in Denver, while accusing Romney of putting on a "theatrical" show to disguise sharply conservative positions.
Another no-show in Tuesday's town hall-style debate before 80 undecided voters, would be deeply damaging for Obama and significantly increase his chances of suffering the historic stigma of a one-term presidency.
Campaigns typically downplay expectations ahead of a debate, but a longtime Obama lieutenant, perhaps recognizing the stakes for Obama's re-election bid on November 6, predicted that the president would come roaring back.
"I think you are going to see an exceptionally strong debate performance tonight from the president," said Robert Gibbs on MSNBC.
"I think you will see somebody who will be strong, who will be passionate, who will be energetic."
Gibbs said Obama would not just talk about the tough four years which America has spent grinding out of an economic crisis, but his agenda for the future - two areas where he lacked passion and focus in Denver.
Romney must prove that his surprisingly assured showing two weeks ago was not a fluke and faces a higher bar of expectations, as his aides busily talk up prospects of an Obama comeback in hopes of managing post-debate news coverage.
"President Obama is going to have a better night than he had at the first debate," Romney spokesman Ryan Williams said, adding that the US leader was likely to "come out swinging with dishonest and negative attacks."
"If the president chooses to attack governor Romney throughout the debate it will simply be another failed chance for him to lay out any kind of rationale or justification for his second term."
Obama has been largely out of sight since Saturday, when he flew to the historic colonial-era city of Williamsburg, Virginia, for an intense debate camp, lent added importance by his limp 90-minute stumble in Denver.
On the eve of the debate, a dramatic intervention from Hillary Clinton, Obama's former bitter Democratic Party foe, and now his secretary of state, may have defused one of Romney's most damaging attacks.
Clinton said she - and not Obama or Vice President Joe Biden - bore responsibility for any security lapses before the attack on the US consulate in Benghazi, Libya on September 11, which killed US ambassador Chris Stevens.
"I take responsibility," she said, according to CNN and Fox, which interviewed her on a visit to Peru.
Romney and his vice presidential nominee Paul Ryan have claimed that the Benghazi raid, and the administration's shifting accounts of it, are symptomatic of an "unraveling" of Obama's foreign policy.
The president was likely to be cross-examined on Libya in Tuesday's debate, but the statement by Clinton, who has political capital to spend, may have given him badly needed room for maneuver.
Another Clinton came to Obama's aide yet again ahead of the debate, the popular 42nd president, in a new campaign video attacking what Democrats say is a $5 trillion tax cut which Romney has no way to pay for.
Bill Clinton appealed to Obama supporters to get to work to convince voters they need to embrace "arithmetic over illusion."
The Romney campaign countered with its own video, claiming growing momentum for the Republican ticket following the first debate.
"The Romney-Ryan plan to create 12 million new jobs to help the middle class is resonating in battleground states across the country as crowds swell, the polls tighten and volunteers flood into (Republican) offices," Republican National Committee chairman Reince Priebus said in the video.
National polls show Romney and Obama locked in a tie, but Romney can claim undeniable momentum in the nine battleground states that will decide who will live in the White House after next January.
A new Quinnipiac University poll Tuesday showed the Republican drawing within four points of Obama in Pennsylvania, a state which many analysts believe the president had already locked down.
Obama has spent many months and millions of dollars arguing Mitt Romney does not care about the middle class. On Tuesday, he faces pressure to prove it, before an audience of voters in the town hall-style debate.
CNN's Candy Crowley will moderate the showdown, with questions posed by about 80 undecided likely voters selected by polling group Gallup.
Some analysts have speculated that the more collegial setting could hamper Obama's efforts to challenge Romney more aggressively than in Denver.
But the president's camp thinks Obama comes across as more likeable and at ease with everyday Americans than Romney, a wealthy former venture capitalist.