Trump made a firm defense of his handling of the pandemic and made the false claim that initial models had predicted that some 2 million Americans were expected to die. Painting a highly misleading picture of the pandemic as cases spike all across the country and hospitalizations begin to rise again, Trump claimed that the US is "rounding the turn."
"We are rounding the corner. It's going away," the President said.
Trump spoke about his own experience fighting Covid-19 and downplayed the current spike, which medical experts have been warning about for months as the country heads into the fall and winter.
"There are some spikes and surges in other places. They will soon be gone," Trump said.
Biden parried with a fierce rebuke of Trump's handling of the pandemic, noting that 1,000 people a day are dying. He focused on Trump's past words -- pointing toward his March statement that he takes "no responsibility" for the slow rate of coronavirus testing growth -- and said his response is disqualifying.
"Anybody that is responsible for that many deaths should not remain as President of the United States of America," Biden said.
"I will take care of this, I will end this, I will make sure that we have a plan," Biden said.
Trump appeared to be working not to lose his temper and the early exchanges were more substantive and controlled than the furious clashes at the start of their first debate. That event was so chaotic that the Commission on Presidential Debates took the unprecedented step of changing the rules before Thursday's showdown: The candidate's microphones will be cut off while their opponent responds to the first question in each of six segments. The topics for the discussion are "Fighting Covid-19," "American Families," "Race in America," "Climate Change," "National Security" and "Leadership."
Pandemic again dominates the debate
The two men offered sharply different visions for the months ahead at a time when cases are rising in more than 30 states. Biden warned that the US is going to have a "dark winter" as the virus begins to rage out of control.
Trump rejected that view and offered upbeat and misleading statistics, including that 99% of people recover. "I don't think we are going to have a dark winter," the President said.
"We are opening up our country," Trump said, adding that the US is "learning to live with it." "We have no choice, we can't lock ourselves up in a basement like Joe does."
Biden rejected Trump's attacks that he would lock down the country and harm the economy.
"I'm going to shut down the virus, not the country," Biden said.
Trump stressed what he views as the dire consequences of too many coronavirus restrictions.
"We can't keep this country closed. This is a massive country with a massive economy. People are losing their jobs," he said. "They're committing suicide. There's depression, alcohol, drugs at a level that nobody's ever seen before. There's abuse, tremendous abuse. We have to open our country. You know, I've said it often -- the cure cannot be worse than the problem itself. And that's what's happening. And he wants to close down -- he'll close down the country if one person in our massive bureaucracy says we should close it down."
"Simply not true," Biden replied.
"We ought to be able to walk and chew gum at the same time. We ought to be able to safely open. But they need resources to open," Biden said of businesses across the country.
Trump looking for a game-changing moment
Desperate to change the current trajectory of the contest, Trump's advisers have been begging him to take a less combative approach on Thursday than in the first debate when he created a virtually unwatchable event by repeatedly interrupting Biden and threading his remarks with personal attacks on the former vice president and his son, Hunter.
The second debate planned between the two men was canceled after Trump tested positive for coronavirus and refused to participate in a virtual debate.
Campaign advisers told CNN's Jim Acosta they now believe it was a huge mistake for Trump to bail on last week's scheduled debate, making a breakout moment a must on Thursday. One adviser said Trump needs a "leadership moment" at the debate as Biden is now seen as the front-runner heading into the final stretch of this campaign. Another adviser said if the President fails in his mission then the President could become increasingly desperate in the final days of this campaign.
Both men face difficult imperatives as they face an audience of tens of millions of people for the last time. Biden is trying to improve his margins with Hispanic voters, in part to shore up his numbers in the key states of Florida and Arizona at a time when he is performing worse with those voters than Clinton did.
Trump is struggling with female voters, who have increasingly gravitated to Biden. And he must also tighten his hold on one of his key constituencies, non-college educated White voters. Trump won those voters by 30 points in 2016, but he currently holds only a 19-point margin within that demographic, according to an analysis by CNN's Harry Enten. Biden, who was born in Scranton, Pennsylvania, has proven to be a more formidable adversary than Clinton when it comes to those voters -- one of the reasons why he is faring better in Midwestern states than the 2016 Democratic nominee.
To bolster his standing, Trump's advisers hope he will be laser-focused on the economy, an area where he has traditionally held a clear advantage over Biden. But Trump has shown little message discipline even in the closing days of this race.
He continues to underperform with seniors, another key constituency he must reach on Thursday, after failing to alter his behavior even after his own Covid-19 diagnosis. Trump is still underplaying the risks of the virus and holding huge rallies with few masks and no social distancing even as the US enters another deadly wave of the virus.
This is a breaking story and will be updated.