Democratic nominee Joe Biden and Republican President Donald Trump squared off Tuesday in their first debate, where they clashed over Supreme Court nominee Amy Coney Barrett and healthcare.

Trump defended his pick for the Supreme Court so close to the election, saying it was justified because he won the 2016 election.

Biden framed the nomination as an attack on the Affordable Care Act, also known as Obamacare. He asserted that if Barrett’s nomination moves forward, millions would lose their insurance.

The first half-hour of the debate often steered into chaos. Trump frequently yelled and spoke over Biden, with Fox News moderator Chris Wallace often intervening.

"Folks, do you have any idea what this clown is doing?" Biden said at one point.

“Will you shut up man?” the former vice president barked at Trump at one point.

Prior to the debate, the Trump campaign was spreading unsubstantianted claims that Biden would be using an earpiece during the event. A pro-Trump ad banner on YouTube’s main page accused Biden of using a teleprompter during interviews.

Biden mocked the pre-debate attacks on Twitter. He tweeted a picture of his earbuds and ice cream, which he jokingly referred to as his earpiece and “performance enhancers.”

Entering the debate, Trump had said Biden should be drug tested. On Sunday, Trump again suggested without evidence that Biden takes performance-enhancing drugs.

“Vice President Biden intends to deliver his debate answers in words. If the president thinks his best case is made in urine he can have at it,” Kate Bedingfield, Biden’s deputy campaign manager, told Politico in a statement Sunday. “We’d expect nothing less from Donald Trump, who pissed away the chance to protect the lives of 200K Americans when he didn’t make a plan to stop COVID-19.”