WASHINGTON — The first presidential debate between President Trump and Joseph R. Biden Jr. unraveled into an ugly melee Tuesday, as Mr. Trump hectored and interrupted Mr. Biden nearly every time he spoke and the former vice president denounced the president as a “clown” and told him to “shut up.”
In a chaotic, 90-minute back-and-forth, the two major party nominees expressed a level of acrid contempt for each other unheard-of in modern American politics.
Mr. Trump, trailing in the polls and urgently hoping to revive his campaign, was plainly attempting to be the aggressor. But he interjected so insistently that Mr. Biden could scarcely answer the questions posed to him, forcing the moderator, Chris Wallace of Fox News, to repeatedly urge the president to let his opponent speak.
“Will you shut up, man?” Mr. Biden demanded of Mr. Trump at one point in obvious exasperation. “This is so unpresidential.”
Yet Mr. Biden also lobbed a series of bitingly personal attacks of his own.
“You’re the worst president America has ever had,” he said to Mr. Trump.
“In 47 months I’ve done more than you have in 47 years,” Mr. Trump shot back, referring to his rival’s career in Washington.
The president’s bulldozer-style tactics represented a significant risk for an incumbent who’s trailing Mr. Biden because voters, including some who supported him in 2016, are so fatigued by his near-daily attacks and outbursts. Yet the former vice president veered between trying to ignore Mr. Trump by speaking directly into the camera to the voters, and giving in to temptation by hurling insults at the president. Mr. Biden called Mr. Trump a liar and a racist.
Mr. Trump peppered his remarks with misleading claims and outright lies, predicting that a coronavirus vaccine was imminent when his own chief health advisers say otherwise, claiming that his rollback of fuel-efficiency standards would not increase pollution and insisting that a political adviser, Kellyanne Conway, had not described riots as useful to Mr. Trump’s campaign, even though she did so on television.
And even as he went on the offensive against Mr. Biden on matters of law and order, Mr. Trump declined to condemn white supremacy and right-wing extremist groups when prompted by Mr. Wallace and Mr. Biden. When Mr. Wallace asked him whether he would be willing to do so, Mr. Trump replied, “Sure,” and asked the two men to name a group they would like him to denounce.
But when Mr. Biden named the Proud Boys, a far-right group, Mr. Trump did not do so and even suggested they be at the ready.
“Proud Boys? Stand back and stand by,” the president said, before pivoting to say, “Somebody’s got to do something about antifa and the left.”
Mr. Trump also intensified his baseless claims of widespread electoral fraud from the debate stage. He again invoked the prospect of a “fraudulent election” and disregarded contrary evidence about mail-in voting offered by both Mr. Wallace and Mr. Biden. And Mr. Trump encouraged his voters to “go into the poll and watch very carefully” for any signs of misconduct — an encouragement that could cause disruption on Election Day.
Mr. Trump’s volcanic performance appeared to be the gambit of a president seeking to tarnish his opponent by any means available, unbounded by norms of accuracy and decorum and unguided by a calculated sense of how to sway the electorate or assuage voters’ reservations about his leadership.
In an election marked by sharply defined and stubbornly stable opinions about both candidates, the president’s conduct was the equivalent of pulling the pin on a hand grenade and hoping that the ensuing explosion would harm the other candidate more.
But Mr. Trump made no effort to address his most obvious political vulnerabilities, from his mismanagement of the pandemic to his refusal to condemn right-wing extremism, and it was not clear that he did anything over the course of the evening to appeal to voters who have disliked him, including those who reluctantly supported him four years ago.
The president did not take aim only at Mr. Biden; he also undercut his own advisers. After Mr. Biden criticized him for his handling of the coronavirus — “he’s a fool on this,” the former vice president said — Mr. Trump mocked his opponent for wearing “the biggest mask I’ve ever seen” and then belittled Dr. Anthony S. Fauci, the nation’s top infectious disease expert.
“He said very strongly ‘masks are not good,’ then he said he changed his mind,” Mr. Trump said of Dr. Fauci. The president later said his own F.B.I. director, Christopher Wray, was “wrong” after Mr. Biden noted that Mr. Wray had said the radical left group antifa is more of an idea than an organization.
The debate, at Case Western Reserve University in Cleveland, quickly descended into name-calling and hectoring in the first 15 minutes, derisive attacks that were extraordinary even by the standards of Mr. Trump’s unruly presidency.
When Mr. Biden attempted to discuss voters who had lost loved ones to the coronavirus, Mr. Trump interjected. “You would’ve lost far more people,” he declared.
The former vice president alternated between smiling and shaking his head in bemusement and firing off attacks of his own as Mr. Trump kept interrupting.
In an exceptionally charged moment, Mr. Trump spoke dismissively about Mr. Biden’s deceased son, Beau, who died from brain cancer in 2015, rejecting an opportunity to show a modicum of personal grace toward his political opponent. Mr. Biden alluded to Beau Biden’s military service as he rebuked the president for having reportedly referred to America’s fallen soldiers as “losers.”
Mr. Trump answered with a rhetoric roll of the eyes, and began attacking Mr. Biden’s other son: “I don’t know Beau; I know Hunter,” he said, proceeding to ridicule Hunter Biden for his business dealings and struggles with drug addiction.
Amid Mr. Trump’s onslaught, Mr. Biden repeatedly offered blanket denials that there was anything inappropriate in Hunter Biden’s overseas work, and said he was “proud of my son” for confronting addiction.
One of the few phases of the debate that might have been taken by an open-minded viewer as an extended and articulate exchange of views came on the subject of the coronavirus pandemic. Mr. Trump voiced impatience with a range of public-health restrictions and Mr. Biden criticized the president for being dismissive of measures like mask wearing and social distancing.
“If we just wore masks between now — and social distanced — between now and January, we would probably save up to 100,000 lives,” said Mr. Biden, who also alluded to the disclosure in the journalist Bob Woodward’s recent book that the president had intentionally misled the American people last winter about the severity of the virus.
Mr. Trump, reiterating his demands that the country return to normal, called on Democratic governors to “open these states up” quickly.
But even on a matter as grave as the pandemic, Mr. Trump indulged freely in personal mockery. When Mr. Biden called him “totally irresponsible” for holding mass rallies without health protections in place, Mr. Trump responded by mocking Mr. Biden’s more constrained events, suggesting the former vice president would hold large events, too, “if you could get the crowds.” The president, at another point, falsely claimed Mr. Biden had finished at the bottom of his college class. “There’s nothing smart about you,” Mr. Trump said to his opponent.
Mr. Biden at times mocked Mr. Trump, recalling at one point the president’s suggestion that people inject disinfectant into their bodies to combat the virus, a gaffe that for a time ended Mr. Trump’s daily briefings. “That was said sarcastically,” Mr. Trump claimed, though his remarks appeared to be in earnest at the time.
For all his evident frustration with Mr. Trump for not abiding by the rules, Mr. Wallace made no attempt to correct the president as he unspooled a series of falsehoods. Mr. Trump, for example, insisted that Mr. Biden had once called criminals “superpredators.” But it was Hillary Clinton who said it, in 1996. And he did not correct Mr. Trump when he said Ms. Conway did not describe riots as helpful to Mr. Trump’s campaign.
In addition to lobbing false allegations, Mr. Trump also was unable, or unwilling, to discuss policy issues in a detailed manner. Pressed on whether he believed in climate change, the president said, “I think to an extent yes,” before quickly adding: “We’re planting a billion trees.”
Overshadowed though it might have been, the policy content of the debate’s opening phase mirrored the stark contrasts already on display in the race. On the Supreme Court, the two men split over whether it was appropriate for Mr. Trump to name a new justice to the court in the final months of his term, with the president offering a defiant rationale for doing so: “We won the election,” he said, “and we have the right to do it.”
Perhaps more surprisingly, Mr. Trump dismissed Mr. Biden’s warning that Roe v. Wade, the Supreme Court decision guaranteeing women’s right to abortion access, was “on the ballot.”
The president projected disbelief, though the decision would plainly be vulnerable to being overturned by a conservative court. “There’s nothing happening there,” Mr. Trump insisted.
Mr. Trump had no defense for Mr. Biden’s warning that if the Supreme Court struck down the Affordable Care Act it could imperil women and people with pre-existing conditions, nor did he offer a substantive response to Mr. Wallace’s question prompting him to articulate a specific vision for health care policy.
The president argued that he had already done so, though he has not, and said that his success in repealing the Obama-era law’s individual mandate was a “big thing” on its own. Instead of finally filling in the blanks of his health care agenda, Mr. Trump sought to go on the attack against Mr. Biden, tying him to the “socialist” aspirations of the left wing of the Democratic Party.
Mr. Biden, who campaigned against socialized medicine in the Democratic primary, deflected the attack — “I am the Democratic Party right now,” he said — and sought to keep the focus on Mr. Trump’s lack of health care policies besides gutting the A.C.A.
“He doesn’t have a plan,” Mr. Biden said. “The fact is, this man doesn’t know what he’s talking about.”
For Mr. Trump, this first debate appeared to be his best chance to change the trajectory of a presidential race that has so far resisted all manner of Trumpian efforts to shake it up. The president has cycled through an array of attacks against his Democratic challenger in recent months, criticizing or outright smearing Mr. Biden’s governing record, personal ethics, economic policies, family finances, and mental and physical health — often relying on misinformation and falsehoods.
Over the last month, Republicans have made an especially concerted push to brand Mr. Biden as overly sympathetic to racial-justice protests that have turned unruly and insufficiently committed to maintaining public order.
Yet that argument has not budged the race an inch in Mr. Trump’s direction, or changed the minds of a majority of voters who take a negative view of his personal character and his leadership during the pandemic. From the outset of the race, Mr. Trump has prioritized his largely rural and conservative base ahead of all other constituencies, and he has done little to reach out to Americans who do not already support him.
Rather, in a year of tumult, there has been one constant: Mr. Biden has enjoyed a steady lead in the polls since he effectively claimed the nomination in April.
Propelled by women, voters of color and whites with college degrees, and faring better with Republican-leaning constituencies than Mrs. Clinton did in 2016, the former vice president is better positioned going into the final month of the election than any challenger since 1992.