President Barack Obama and his Republican challenger Mitt Romney are making final preparations for the first of three crucial presidential debates.
With just 34 days to go until election day, Wednesday’s Denver debate will focus on domestic policy issues.
Mitt Romney has long criticized the president for his economic record, but is likely to face questions over his own tax plans and immigration policy.
Barack Obama has opened up a narrow lead in the race over the past month.
He leads Mitt Romney in national polls and in many recent polls conducted in the swing states that will decide the election.
The latest national survey, released on Tuesday by NBC News and the Wall Street Journal, shows Barack Obama leading, but by just 49% to 46%.
Mitt Romney has struggled in the polls since a secretly filmed recording emerged of him telling a private fundraising event that the 47% of Americans who did not pay income tax viewed themselves as “victims” and were dependent on government help.
Wednesday’s debate at the University of Denver will be the first time voters across the US have had the chance to see Barack Obama and Mitt Romney on stage together.
Both men have already been on the campaign trail for months, and used their prime-time speaking slots at the recent party conventions to make their case to voters.
An even bigger audience is expected for this first debate: the opening head-to-head of the 2008 election attracted more than 50 million TV viewers across the US.
The candidates’ body language will be heavily scrutinized, as will their tone of voice and how they handle themselves under pressure. Media pundits and campaign spin doctors will attempt to seize on any gaffe or mis-statement in an effort to claim victory.
Both campaigns have been playing down their man’s prospects in the run-up to the debate, with Barack Obama praising his opponent’s debating skills and Mitt Romney’s running mate Paul Ryan insisting that one debate alone will not change the campaign.
Nevertheless, both candidates’ messages are well-honed, and their sharp words for each other are familiar to millions of swing-state voters who have faced a onslaught of mostly negative TV advertisements in recent months.
Mitt Romney’s campaign is based around his belief that Barack Obama’s stewardship of the US economy has been a dismal failure. He points to an enduringly high unemployment rate (currently 8.1%) and poor job growth, and says his experience in business will turn the US economy around.
Barack Obama, by contrast, says his opponent offers little except a rehashing of the “failed” Republican policies that caused the economic crash of 2008.
The president proposes tax rises for the wealthiest Americans to help reduce the federal budget deficit, and says his opponent’s plans would hurt the middle class.
But critics say neither man has fully fleshed out his economic policies, and doubts remains about how either Republican or Democrat will tackle the $15 trillion US deficit.
The two candidates have been largely absent from the campaign trail in recent days, shutting themselves away with aides for hours of rigorous preparation and practice.
Mitt Romney, who is known for his meticulous approach to debates, arrived in Denver on Monday and has been using Ohio Senator Rob Portman to play the role of Barack Obama.
The president, meanwhile, has been preparing in Las Vegas, Nevada, with 2004 Democratic nominee John Kerry reportedly playing Mitt Romney.
With the principals waiting in the wings, Tuesday saw vice-presidential candidates Joe Biden and Paul Ryan take centre stage.
Joe Biden stole the headlines, telling a campaign rally in North Carolina that the US middle class had been “buried” for four years. The remark was seized on gleefully by the Romney campaign.
“Of course the middle class has been buried,” Paul Ryan said in Iowa later on.
“They’re being buried by the Obama administration’s economic failures.”
Presidential election debates 2012:
• October 3rd: Denver, Colorado. Domestic policy. Moderated by Jim Lehrer (PBS)
• October 11th: Danville, Kentucky. Vice-presidential debate. Moderated by Martha Raddatz (ABC)
• October 16th: Hempstead, New York. Town-hall style foreign policy debate. Moderator: Candy Crowley (CNN)
• October 22nd: Boca Raton, Florida. Moderator: Bob Schieffer (CBS)