The first presidential debate Tuesday quickly devolved into name-calling, shouting, and personal insults as President Donald Trump rattled off attacks against Democrat Joe Biden, unfettered by a moderator who struggled to keep calm.
Pressed repeatedly, Trump refused to condemn extremist supporters or urge them to stay peaceful in the event of a disputed election, including the white supremacists and far-right militia groups that support him and committed recent acts of violence in his name.
"Proud Boys, stand back and stand by," Trump said, referring to one group the FBI has characterized as an extremist group with ties to white nationalism. "But I'll tell you what, somebody's gotta do something about Antifa and the left."
Biden called Trump a "racist," "clown" and "the worst president we've ever had," at one point saying, "Will you shut up man?"
Biden enjoyed a comfortable and consistent lead in most national polls and only a tiny fraction of voters remain undecided, so the pressure was on Trump to shake things up in the waning weeks before Election Day.
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Trump attacked Biden's son, Hunter, and accused the former vice president of supporting socialism.
"I’ve done more in 47 months than you’ve done in 47 years."
Moderator Chris Wallace tried to tamp down the antagonistic president, but his efforts to keep calm were quickly stymied as Trump refused to let his opponent speak uninterrupted for more than a moment.
When Biden said that Trump needed to be smarter about his response to coronavirus, the president interrupted to argue that Biden was himself not intelligent. He pointed to Biden's position in his college graduating class as evidence.
"Don't ever use the word smart with me. You're not smart, Joe," Trump said.
Biden frequently tried to paint Trump as dishonest, including in how he presented the coronavirus to America.
"The fact is that everything he has said tonight is a lie. Everyone knows he's a liar," Biden said.
At one point, Trump interrupted by asking, “Can I be honest?”
“Try to be honest," Biden replied sarcastically.
Wallace tried to reassert control, but Trump fired back at that the Fox News anchor was "fake news." Eager to portray himself as being ganged up on by a tag-team of the Democrats and the mainstream media, Trump said, "I guess I'm debating you, not him. But that's OK."
The candidates clashed over re-opening schools and businesses during the coronavirus pandemic, with Trump claiming Democratic governors and mayors are keeping things closed until after the election to damage the president's re-election chances.
"They think they're hurting us by keeping it closed, they're hurting people," Trump said. "And this guy will close down the whole country -- he will destroy our country.”
Trump has bet his reelection on convincing the American public he successfully handled the coronavirus crisis, believing that swing voters are growing tired of social distancing and COVID concerns and more concerned with getting their kids back in schools.
"I'm the one who brought back football," Trump said, taking credit for the Big Ten deciding to reopen their season. And he mocked Biden for always wearing a mask. “He could be speaking 200 feet away, and he shows up with the biggest mask I've seen."
And he defended holding large campaign rallies against the guidance of experts to avoid large crowds. "People want to hear what I have to say," Trump said.
Biden said reopening too soon will hurt workers and said the Trump administration had not provided enough resources to help schools safely re-open. "You can’t fix the American economy until you fix the COVID crisis," Biden said.=
Presidential debates typically take place in front of thousands in packed theaters. But the scaled-down crowd made the event feel unusually small and intimate inside the room, where members of Congress and other VIPs invited by the campaign spoke in hushed tones.
Just months ago, the room served as a possible Covid-19 reserve ward, with 1,000 hospital beds ready to handle an expected surge of cases in Ohio that fortunately never came.
Trump and his allies spent the hours leading up to the debate lobbing baseless accusations against Biden. First, Trump attacked him for declining to take a drug test, then accused him of trying to avoid detection of a secret earpiece. Biden's campaign dismissed the claims as ludicrous said he, of course, would not wear an earpiece.
The earpiece theory — Donald Trump Jr. made the same unfounded claim in 2016 about Hillary Clinton — started in viral memes on Facebook and other social media sites before being repeated by the Trump campaign.
A version of this story originally appeared on NBCNews.com.