The 90-minute debate quickly descended into chaos after Trump began to interrupt both Biden and the moderator, Fox News' Chris Wallace. The night didn't get much calmer from there.
Read highlights from Tuesday's debate below:
Trump family members ignore mandatory mask rule
The Trump family and other members of the administration entered the debate hall, where rules mandated everyone in the room wear masks, without masks.
From your pool era vantage point, all family members who entered without a mask, members of his administration and other guests were not wearing a mask. A Cleveland Clinic doctor in a white lab coat started to approach Trump family guests to ask them to put on masks. She offered them one in case they didn’t get one. She never approached any family members but as she got closer to them, someone shook their head and no one she reminded to put on a mask ended up putting one on.
Jill Biden, Sen. Chris Coons and others sitting in the Democratic section began to look over. Trump family members began to ask their guests what had happened.
When the doctor, who refused to comment to the press, walked off the floor, a debate hall staffer told her “That’s all you can do."
Fact-check: Biden says GOP lawsuit 'will strip 20 million people' of their insurance
Biden claimed that the Republican-backed lawsuit targeting Obamacare would strip 20 million people of their health care coverage.
This checks out, according to multiple studies. The Center for American Progress estimated in a recent analysis that 23.3 million would lose their health care if the GOP-backed legal challenge to the law succeeds before the Supreme Court. An estimated 20 million people gained coverage under Obamacare, according to the Kaiser Family Foundation.
In the first 20 minutes, both candidates stay mostly on topic
Health care and the Supreme Court dominated the first 20 minutes of the debate. Both Trump and Biden stayed mostly on topic. Follow our live tracker here.
Supreme Court debate turns into a health care battle
The argument over having Amy Coney Barrett confirmed to the Supreme Court quickly turned into a battle over health care policy.
Barely any time was spent on the Supreme Court nomination before Trump and Biden began debating health care policy.
But there was barely any “debate” over their policies. Trump repeatedly interrupted Wallace and Biden. Barely any complete sentences were said.
Wallace, who wanted to be 'invisible,' spars with Trump
Trump has come out the gates with energy, but Wallace has interrupted Trump to let Biden speak and then sparred with the president over a question on health care and the Affordable Care Act.
After a back and forth in which Trump repeatedly interrupted Wallace, Wallace fired back, "Sir, you're debating him, not me. Let me ask my question."
First question takes on Supreme Court
Wallace opened the debate by asking both Trump and Biden about why they’ve got the right take on the Supreme Court vacancy.
Trump said he has the right to nominate Amy Coney Barrett because Republicans control both the Senate and White House.
"We won the election and we have the right to do this," Trump said.
Biden argued that the American people have a right to say who is on the court and that we should wait to see the outcome of the election.
Interestingly, he does not personally bash Barrett but argued that her conservative stance would be harmful to the court for people in the county who have pre-existing conditions because Obamacare could be struck down.
Biden got into long crosstalk with Trump about the question, which set the tone for the contentious debate.
Wallace debunks conservative conspiracy theory off the bat
In his intro, Chris Wallace took a moment to knock down one of the many conspiracy theories that have circulated about the debate.
Wallace said the questions were from him and that neither candidate had received them ahead of time. "For the record, I decided the topics and the questions in each topic. I can assure you, none of the questions has been shared with the commission or the two candidates," Wallace said.
Debate moderator Chris Wallace isn't like other Fox News hosts
Fox News host Chris Wallace opened the debate on Tuesday shortly after 9 p.m. ET.
Wallace, the host of Fox News Sunday, has built a reputation for his interrogative style of interviewing. Unlike other hosts on the network — who have been criticized for cheerleading for the administration and Trump (including Sean Hannity) — Wallace has tried to model himself as an evenhanded journalist who is seen by some on both sides of the aisle as serious and sharp.
He was one of the moderators of the 2016 GOP presidential debate in Detroit when he famously used slides to fact check then-candidate Trump in real-time. He also moderated the third presidential debate during the 2016 campaign, pressing both Clinton and Trump with substantive questions and pressing further for a substantive answer.
Wallace has criticized Biden for not appearing on his show since becoming the Democratic nominee to be cross-examined over his policies. And Wallace’s style has caused Trump to lash out at him over the years — like when Trump called him a “Mike Wallace wannabe” (the moderator’s famous journalist father) in an April tweet. Wallace also clashed with Trump in a July interview in which the journalist cast doubt on the president’s that his mental fitness test was difficult.
"I took the test, too, when I heard that you passed it," Wallace told Trump who said he aced the test. "It's not the hardest test," noting that one of the questions asks you to identify a drawing of an elephant.
Who will stay on topic? We're tracking the candidates during the debate
Track what Trump and Biden talk about, and how much they stay on-topic, at tonight’s debate.
We just got started. You can follow along here.
'Dump Trump': Peaceful protests against the president at first debate
Hundreds of protesters demonstrated at the presidential debate near the Health Education Campus of Case Western Reserve University in Cleveland on Tuesday, shortly before Trump and Biden were set to hold their first faceoff.
The coalition of left-wing groups aimed their ire at the president, chanting slogans like "Dump Trump" and holding "Black Lives Matter" signs. They also chanted the name of Tamir Rice, a Black 12-year-old boy who was killed by police in Cleveland in 2014.
Protesters were kept blocks away from the debate site by a combination of state police and the National Guard, who'd established an "event zone" around the area.
Here's the vibe inside the hall pre-debate
What’s the vibe like inside the debate hall? It feels remarkably intimate and more muted than the pre-debate tee-up in years past. It’s oddly quiet, even though the room has started to fill— a relative term, considering the socially-distanced seats in effect— and people are beginning to sit.
Some of the seats are labeled. Among the names spotted by our producer: Donald Trump Jr, Tiffany Trump, Melania Trump, Ivanka Trump, Eric Trump, Ohio Rep. Jim Jordan, Lara Trump, Kimberly Guilfoyle, chief of staff Mark Meadows, RNC chair Ronna McDaniel, Blake Meadows, Phoebe Meadows and Dr. Jill Biden.
The mask requirements have made spotting notable guests in the crowd a bit more challenging, but we’ve seen Delaware Sen. Chris Coons, Ohio Rep. Tim Ryan, Arizona Rep. Ruben Gallego, political consultant Frank Luntz, Los Angeles Mayor Eric Garcetti, DNC chair Tom Perez, Illinois Rep. Cheri Bustos and Jim Jordan.
We’re approximately 15 minutes from the start time.