Presidential Debate Live Preview: Biden vs. Trump Updates

To Mr. Trump’s supporters, it was a signal that his denial of climate change had not shifted. To his detractors, it was still more proof that he will not accept established science. But according to three people who witnessed the event, it was all theater.

A few minutes later, out of the range of television cameras, Mr. Trump readily agreed with Gov. Gavin Newsom that climate change in fact did exacerbate the wildfire season.

He called its responsibility “probably like 50-50,” along with poor forest management, the people familiar with the discussion said.

Judd Deere, a White House spokesman, said in a statement the remarks were “not a correct reading of the conversation.”

But the president’s casual, semiprivate acknowledgment of climate change stunned several observers, some of whom likened it to the president’s admission to journalist Bob Woodward that he deliberately downplayed the coronavirus despite knowing it was “deadly stuff.”

At the California event, Governor Newsom approached Mr. Trump after the briefing had ended and the press pool had departed. He said he hoped the president understood that California leaders felt it was important to raise the issue of climate change despite their different views, according to the observers, who asked not to be named because they were not authorized to discuss the conversation.

“Gavin, I totally get it, and really it’s probably like 50-50,” President Trump replied, according to those who overheard.

Scientists said whether or not Mr. Trump was purposely provoking outrage on the left to delight his base, his equivocating on climate change was dangerous.

“Published science shows that pollution from human sources causes 98 percent of the heat of climate change and that human-caused climate change has doubled wildfire over natural levels in the western U.S. On both issues, Mr. Trump is wrong,” said Patrick Gonzalez, a forest ecologist and climate change scientist at the University of California, Berkeley.

“When Mr. Trump denies science and blocks action on climate change, he puts people’s lives and homes at risk,” Dr. Gonzalez said.

Particularly in a year when live broadcasts have had to shift online in response to coronavirus concerns, the mute button has become even more important. When a Supreme Court oral argument in Barr v. American Association of Political Consultants was being live-streamed in May, a hilariously inopportune toilet flush (claimed by no one) would have been better left unheard.

And when Senator Tom Carper, Democrat of Delaware, shouted expletives into a mic he didn’t know was on during a virtual Senate hearing on the Postal Service in August, a hot-button issue became a laughing matter.

Politics is not the only arena that benefits from muted mics, as working from home has presented a range of new challenges, being interrupted by family members in the background not the least among them.

In one memorable instance this summer, Clare Wenham, an assistant professor at the London School of Economics, was being interviewed on BBC about the U.K. lockdown when her daughter interrupted with a question. “Mummy, what’s his name?” the girl asked her mother about the interviewer.

Mr. Biden has built a formidable polling advantage over Mr. Trump on the coronavirus crisis: By double-digit margins, voters say they trust him over the president to handle it.

It’s not quite clear what the debate’s moderator, Kristen Welker, has planned for the section titled “American families,” but a range of polling data shows that voters remain shaken by the pandemic’s effects and uncertain about what the future holds. The recent New York Times/Siena poll found that 50 percent of likely voters said they were actually better off than four years ago, while just a third said they were doing worse. But when asked about the country at large, 55 percent said things had grown worse.

Among Americans — including white voters not in the Republican Party — concern about anti-Black discrimination hit a record high this year. Partly as a result, voters overwhelmingly pick Mr. Biden as the better option to handle racial issues. In an ABC News/Ipsos poll last month, voters said Mr. Biden would do a better job handling issues of racial discrimination than Mr. Trump would by roughly two to one.

Republicans have grown more likely to say that it is white people who face bias, according to polling from the Public Religion Research Institute: 57 percent of Republicans said white people faced a lot of discrimination in the institute’s 2020 American Values Survey. Members of Mr. Trump’s party are now more likely to say that white people or Christians face a great deal of discrimination than they are to say that about Black people, the survey found.

Mr. Trump has consistently denied the science of climate change, leaving him out of step with most Americans — including, at this point, members of his own party. Nearly two-thirds of Americans said they thought the government was doing too little to confront climate change, according to a Pew Research Center poll this year. It found majorities of both Democrats and Republicans supporting a range of federal measures to confront global warming.

By a huge margin — 58 percent to 19 percent — registered voters said in an NBC News/Wall Street Journal poll that Mr. Biden would handle the response to climate change better than Mr. Trump.

Voters have been evenly split on whether Mr. Trump was being too hostile to America’s traditional allies (43 percent said yes) or handling those allegiances well (44 percent), according to a Quinnipiac University poll last year.

Americans broadly think Mr. Biden would do a better job of handling foreign policy. Fifty-nine percent chose him on the issue, according to a CNN poll last month, compared with just 39 percent who picked Mr. Trump.

In 2016, Mr. Trump consistently scored ahead of Hillary Clinton in polls measuring whom voters considered to be the “stronger leader.” But when asked in an ABC News/Washington Post poll last year whether they thought he had the right personality and temperament to do the job of president, 62 percent of Americans said no, while just 36 percent said yes.

Asked in a CNN poll this month whom they considered more honest and trustworthy, Americans chose Mr. Biden over Mr. Trump, 57 percent to 33 percent.

• Kristen Welker of NBC News will moderate the debate, which will take place in Nashville.

• It will begin at 9 p.m. Eastern and run for 90 minutes. The announced topics include fighting the coronavirus, American families, race in the United States, climate change, national security and leadership.

• The New York Times will cover the event live, with real-time analysis from teams of reporters, on nytimes.com.

• The debate will be televised on channels including ABC, CBS, NBC, CNN, C-SPAN, PBS, Fox News and MSNBC. Many news outlets, including ABC, CBS, NBC, PBS, Fox News and C-SPAN, will stream the debate on YouTube.

Since the beginning of the pandemic, Mr. Trump has downplayed the threat from the virus and has ignored advice from health officials, refusing to wear a mask and holding gatherings with large crowds. His administration’s failures to rapidly expand testing are also well documented.

Mr. Biden’s plans call for improved testing, expanded production of personal protective equipment, safe vaccine development and the safe reopening of schools. He has emphasized the importance of following science, and he has modeled responsible behavior on the campaign trail, wearing a mask and refraining from holding crowded rallies.

Mr. Trump repeatedly claims to have done more for Black Americans than any president other than Abraham Lincoln, an assertion that most experts say is absurd on its face. The president points to his support for long-term funding for historically Black colleges and universities, and to his signing of the bipartisan First Step Act, which made modest reforms in federal sentencing laws.

But from the earliest days of his presidency, Mr. Trump has stoked racial divisions. After clashes between white supremacists and counterprotesters at a rally in Charlottesville, Va., in 2017, he said that there were “very fine people on both sides.” He used vulgar language to deride African nations and said that Haitian immigrants “all have AIDS.” And in the first debate, he refused to denounce the Proud Boys, a far-right extremist group, telling them to “stand back and stand by.”

Since the death of George Floyd in police custody in May, Mr. Biden has emphasized the need to fight racial injustice, speaking about the issue in a strikingly different way than Mr. Trump does. This summer, Mr. Biden rolled out a plan to address economic racial disparities, such as by increasing access to capital for minority-owned businesses. He has also called for changes in policing, including a ban on chokeholds.

Mr. Trump has called climate change a hoax and called those who care about the issue “prophets of doom.” Mr. Trump has moved to withdraw from the Paris agreement on climate change and has rolled back virtually every regulation aimed at reducing emissions from vehicles, power plants and other sources. He has promoted the development of fossil fuel energy, and made it easier for aging coal plants to stay online.

Mr. Biden has attacked Mr. Trump as a “climate arsonist,” criticized the president’s dismissiveness of science and championed a $2 trillion plan to develop clean energy while driving down emissions. But he also has been on the defensive about the Green New Deal, a climate plan embraced by progressive groups and criticized by Republicans. In his first debate with Mr. Trump, Mr. Biden said he did not support the Green New Deal, but his website calls it a “crucial framework” for action.

Another area where Mr. Biden is likely to come under attack from Mr. Trump is fracking, the process of extracting oil and gas from shale rock. Mr. Biden has pledged a ban on new oil and gas permitting on public lands and waters, but he has assured union leaders that he will protect existing fracking jobs while pursuing a clean energy transition. Mr. Trump has accused him, falsely, of wanting to ban fracking altogether.