President Donald Trump and former Vice President Joe Biden hurled insults and repeatedly interrupted and talked over each other in their first debate, sparring over topics ranging from health care to the economy and their families as moderator Chris Wallace tried mostly in vain to control the conversation.

Biden repeatedly called Trump a “clown” and told him to “shut up” as Trump talked over his answers. He called the president a “racist” after Trump defended his orders to end racial sensitivity training in the government.

Trump insulted Biden’s intelligence and jabbed the former vice president over unsubstantiated allegations about his son Hunter Biden’s foreign business dealings. Biden called Trump “the worst president America’s ever had.”

The back-and-forth quickly degenerated after Trump answered the first question, about his nominee to replace the late Supreme Court Justice Ruth Bader Ginsburg. Trump said he had the right to move swiftly to replace her, while Biden said U.S. voters should weigh in first.

“We won the election,” Trump said in answer to the first question, about his nominee Amy Coney Barrett. “Elections have consequences. We have the Senate, we have the White House and we have a phenomenal nominee.”

Biden said that Trump and Barrett want to strike down the Affordable Care Act, costing 20 million people their health insurance.

“The American people have a right to have a say over who the Supreme Court nominee is,” Biden said. “What’s at stake here, as the president’s made it clear, he wants to get rid of the Affordable Care Act. He’s in the Supreme Court right now trying to get rid of the Affordable Care Act, which will strip 20 million people from having health insurance now, if it goes to the Supreme Court.”

The debate moderator, Fox News host Wallace, tried to intervene as the two candidates squabbled over their respective health policies, and Trump complained: “I guess I’m debating you.”

“Folks, do you have any idea what this clown is trying to do?” Biden, who frequently spoke directly into the camera, said as Trump talked over him. “Will you shut up, man,” he grumbled moments later.

Wallace subsequently asked about Trump’s response to the coronavirus pandemic, which has killed more than 200,000 Americans so far, and why voters should trust Biden to handle the response better.

“You don’t panic. He panicked,” Biden said. “He still doesn’t have a plan.”

“Wrong,” Trump interjected.

“You could never have done the job that we did. You don’t have it in your blood,” he told Biden, alleging “millions” of Americans would have died with the former vice president leading the country.

“I know how to do the job,” Biden said. “I know how to get the job done.”

After enduring Biden’s criticism of his coronavirus response, Trump seized on a Biden remark that his management of the crisis would be “smart.”

“Don’t ever use the word ‘smart’ with me,” Trump said, accusing Biden of forgetting where he went to college.

Biden chuckled. “Oh give me a break.”

“There’s nothing smart about you, Joe,” Trump added.

Trump and Biden even argued about whether Americans should wear masks to combat spread of the virus. Many people in Trump’s entourage in the audience didn’t wear one, and when an official from the Cleveland Clinic, which is co-hosting the debate, came by to offer them masks, they refused.

Biden’s entourage wore masks. He noted that the director of the Centers for Disease Control and Prevention said earlier this month that near-universal mask wearing would end the U.S. outbreak. Trump said other officials had claimed the “opposite.”

“No serious person said the opposite,” Biden said.

“I think masks are OK,” Trump said. “I mean I have a mask right here. When needed, I wear masks. I don’t wear masks like him.”

Hours before the debate began, Biden released his most recent tax returns, signaling that he wanted new revelations about the president’s taxes at center stage for their first face-to-face encounter.

“Is it true that you paid $750 in federal income taxes” in 2016 and 2017, Wallace asked Trump, a reference to New York Times reporting beginning Sunday on tax records the president has kept secret.

Trump didn’t directly answer, saying he paid millions of dollars in taxes. “Show us your tax returns,” Biden interjected.

“I paid $38 million one year, I paid $27 million one year,” Trump said, without specifying which years.

“Will you tell us how much you paid in federal income taxes in 2016 and 2017?” Wallace repeated.

“Millions of dollars,” Trump answered. “And you’ll get to see it.”

The difference between the two candidates’ tax history is fodder for Biden’s argument that Trump has conned working-class voters into supporting him.

Biden paid nearly $300,000 in income taxes in 2019, according to his returns. Billionaire Trump, meanwhile, paid $750 in 2016 and 2017, and nothing in ten of the last 15 years, according to the New York Times.

After the discussion of Trump’s taxes, a question about Trump’s economic record degenerated into arguing — again in personal and insulting terms — over China and the two candidates’ families.

“You take a look at what he’s actually done. He’s done very little,” Biden said. “China’s perfected the art of the steal.”

Trump used the criticism as an opening to attack Biden’s son Hunter Biden, demanding to know whether he had taken “billions of dollars” from China and alleging “the mayor of Moscow’s wife gave your son three and a half million dollars.”

Biden audibly sighed. “That is not true,” he said. “It’s totally discredited.”

Trump began talking over him again, insisting the claim was only discredited by the media.

“It’s hard to get any word in with this clown,” Biden said. “His family, we could talk about all night.”

Trump said some of his family had given up comfortable lives to move to Washington and help him govern. Wallace ended the back-and-forth by admonishing the two men not to interrupt each other, focusing on Trump, who he said had been the worst about it.

After Wallace asked Trump to explain actions he’s taken to end racial sensitivity training in the government and by federal contractors, Trump said that “I ended it because it’s racist” and “they were teaching people to hate our country, and I’m not going to allow that to happen.”

“Nobody’s doing that,” Biden responded. “He’s the racist.”

The tax returns Biden released Tuesday showed he paid a 31.7% income tax rate, giving strength to his argument that he has more in common with the White, working class voters he needs to win back from Trump than the president himself — even if that rate was on income of $944,737.

Tuesday’s presidential debate, the first of three before the Nov. 3 election, is hosted by Case Western Reserve University as well as the Cleveland Clinic.

The topics, which were announced last week by the Commission on Presidential Debates, include a comparison of the Trump and Biden records, the Supreme Court, the coronavirus, the economy, racial tensions, the violence in U.S. cities and the integrity of the election itself.

With five weeks left until Election Day, polls show Biden leading Trump nationally and in key swing states. The Democrat’s campaign has approached the debate as a high-stakes moment when he could cement his advantage or see it begin to erode.

Biden, an experienced debater after previous presidential and vice presidential bids and 36 years in the Senate, has previewed an approach focused on what he considers Trump’s failures, including “criminal” mismanagement of the pandemic. He will also seek to portray a second Trump term as one that would cause irreparable harm to U.S. democracy.

For Trump, the debate is a critical opportunity to try to regain momentum after months of declining poll numbers.

While debaters traditionally seek to raise expectations for their opponents, Trump and his allies have for weeks lowered the bar for Biden, 77, by arguing that he is mentally impaired and exhausted. Only recently have Trump surrogates begun to focus on Biden’s experience in the forum.

That strategy could backfire. The coronavirus has sharply restricted the candidates’ ability to campaign, though Trump has resumed large in-person rallies. The debate will be the first opportunity for many voters to see Biden on a stage since the Democratic convention and he might only have to hold his own for the showdown with Trump to be declared a success.

But for some Democrats, a single gaffe or missed opportunity to take a swipe at Trump is likely to be cause for worry. Trump and his supporters, meanwhile, are likely to declare victory no matter what.