Republican candidate Mitt Romney is under pressure to produce a strong performance on Wednesday at his first face-to-face debate with President Barack Obama to try to turn around a race for the White House that has been edging away from him.
The 90-minute encounter offers the chance to reach more than 60 million people on television, a far greater audience than watched either candidate speak at the Democratic and Republican conventions.
While that has potential dividends in attracting undecided voters, there is also the risk that one or the other will make a major mistake that can overshadow the campaign in the last five weeks before the November 6 election.
Running behind in the polls, Romney is more in need of a victory than Obama at the University of Denver debate, the first of three such face-offs scheduled in the next four weeks.
"I think he's got to have a pretty convincing win," said David Yepsen, director of the Paul Simon Public Policy Institute at Southern Illinois University. "He's had a bad few weeks and he needs to change the narrative of the campaign."
The Republican was damaged by a secretly taped video from a private fundraiser in which he said 47 percent of voters are dependent on government and unlikely to support him. It was only one of several recent stumbles by the former Massachusetts governor in his second presidential bid.
At the Denver debate, Romney needs not only to repair some of the damage from the video. He must raise questions about Obama's handling of the U.S. economy and explain how his own plan would create more jobs and cut the budget deficit.
Romney must get through the debate without losing his cool and without appearing to be disrespectful to Obama, who many Americans like personally despite his struggle to create jobs. And the often robotic Republican could do with showing some personality to make voters feel more comfortable with him.
"Americans who are thinking about voting for Romney need to hear from him about how he would change the country for the better," said Republican strategist Ron Bonjean. "They're leaning toward the devil they know, which is President Obama. Romney has to knock it out of the park by showing the contrast between himself and Obama."
ECONOMIC CHALLENGES FOR OBAMA
The Democrat has the challenge of answering why Americans should consider themselves better off now than they were four years ago, a key measure in every presidential election. He needs to explain what he would do to rekindle job creation in a second term.
The U.S. jobless rate has been above 8 percent for 43 straight months and is the top priority of voters. The Obama camp argues he inherited a tough economy from Republican predecessor George W. Bush. Many voters seem willing to cede him that point but nonetheless are looking for a clear way out of the economic doldrums.
"He's got to reassure people who like him that it's OK to vote for him again," said Yepsen. "I think Americans like the man; they're a little bit concerned about the job he's done. And he's got to bring them back home."
Obama is considered far more likable than Romney and leads him on many attributes in opinion polls. He has the edge over Romney in many battleground states such as Ohio where the election will be decided.
So far, Obama has offered little in the way of a second-term governing agenda beyond more of the same policies, amid rising debt, budget deficits and increasingly expensive entitlement programs. His first term has been marked by fierce partisan battles that have frozen Washington into political gridlock.
Obama's campaign has cast Romney as a wealthy elitist who is out of touch with the plight of everyday Americans.
Body language will be closely watched to see if Obama can fight a tendency to be condescending and professorial and whether Romney can resist arguing about the debate rules or who gets the most time to speak, as he did during Republican primary debates.
Both men found some late news that could help them make their cases at the debate, which will be moderated by Jim Lehrer of PBS and starts at 9 p.m. Eastern time (0100 GMT).
The Obama camp seized on a New York Times article that said Romney had benefited financially on his offshore holdings. The Obama campaign charged that Romney had "failed to come clean with the American people."
A comment from Vice President Joe Biden gave the Romney campaign an opportunity. Biden accused Romney of seeking to raise taxes on America's middle class, which he said "has been buried the last four years."
"Of course the middle class has been buried," said Romney's vice presidential running mate, Paul Ryan. "They're being buried by regulations; they're being buried by taxes; they're being buried by borrowing. They're being buried by the Obama administration's economic failures."
Experts are not necessarily in agreement on whether debates can serve as a turning point in a presidential election.
But history shows there are plenty of cases where they have cast some candidates in a negative light, from Al Gore's heavy sighs and eye-rolling during a 2000 debate with George W. Bush to Richard Nixon's profuse sweating during his encounters with John F. Kennedy in 1960.