President Donald Trump and his challenger Joe Biden have fiercely clashed in one of the most chaotic and rancorous White House debates in years.

Amid angry shouting and name calling, the two fought over the pandemic, race and the economy during the 90-minute forum in Cleveland, Ohio.

Mr Biden called the president a "clown" and told him to "shut up". Mr Trump brought up his rival's son's drug use.

Opinion polls indicate Mr Biden has a steady single-digit lead over Mr Trump.

But with 35 days until election day, surveys from several important states show a closer contest.

The forum focused on six topics in 15-minute segments - the candidates' records, the Supreme Court, the pandemic, race, election integrity and the economy.

• LIVE: Nasty clashes between Trump and Biden
• Who won the Trump-Biden debate?
• A simple guide to the US election

In a vitriolic back and forth punctuated by insults, Mr Biden, 77, accused Mr Trump, of stoking "racist hatred", and labelled him "Putin's puppy" in reference to Russia's president.

He also told his rival: "You're the worst president America has ever had."

What did they say about coronavirus?

Due to the coronavirus pandemic, the debate at Case Western Reserve University had a small, socially distanced audience and the traditional opening handshake was skipped.

Mr Biden rubbished Trump's leadership on the coronavirus pandemic, which has killed more than 200,000 Americans.

"He panicked or he looked at the stock market," the Democrat said of the president, who wants states to reopen their economies.

"A lot of people died and a lot more are going to die unless he gets a lot smarter, a lot quicker," Mr Biden said.

Mr Trump objected to Mr Biden using the word "smart."

"You graduated either the lowest or almost the lowest in your class," the president said. "Don't ever use the word smart with me. Don't ever use that word."

A food fight

In a debate that was the political equivalent of a food fight, the winner is the man who emerged least covered in slop.

On Tuesday night, that man was Joe Biden - if only because his main goal was to prove to Americans that he could hold up under pressure, that he had not lost a step due to his advancing age. He had to show he could take a pie to the face, metaphorically speaking, and keep his cool.

He mostly met that standard, although it was at least in part because Donald Trump, by his constant hectoring and interruptions, seldom gave the former vice-president a chance to say something truly damaging to his own cause.

Twitter Trump - the unconventional, bombastic, insulting and rumour-mongering aspect of this president - was on full display throughout the hour and a half event. Unfortunately for the president, many Americans, even his own supporters, find his social media persona one of his more unattractive attributes.

Trump needed this debate to shake up a race that is tilting against him - and has been remarkably stable, through economic, health and social adversity.

Nothing about this hour-and-a-half free-for-all seems likely to alter the dynamics of this contest or change the minds of the one in 10 American voters who say they are still undecided (although perhaps they'll resolve never to watch another one of these).

Anything resembling a substantive exchange was buried in a cavalcade of bloviation and bickering - and because of this, it was a missed opportunity for the president.

• Who won the Trump-Biden debate?

What did they argue over in the opening minutes?

As the two tussled over healthcare, Mr Trump, a Republican, accused his rival of being beholden to socialists in his party, saying: "They're going to dominate you, Joe, you know that."

"Right now I'm the Democratic party," retorted Mr Biden.

Mr Biden went on: "Here's the deal: everything he's saying so far is simply a lie.

"I'm not here to call out his lies. Everybody knows he's a liar."

Mr Trump hit back: "Joe, you're the liar."

The president then defended his effort to swiftly fill a US Supreme Court seat to cement a 6-3 conservative majority on the bench.

Mr Trump challenged his rival to say whether he would pack America's highest court, adding more justices to tilt its ideological balance, as some Democrats have urged.

The president also demanded Mr Biden release a list of his own judicial nominees.

But Mr Biden would not be drawn. "Will you shut up, man?" the Democrat said.

"Who's on your list, Joe?" Mr Trump pressed. "He's going to pack the court."

The moderator, Chris Wallace, cut in to move the debate on.

"Keep yapping, man," Mr Biden said.

Mr Trump replied: "The people understand, Joe. Forty-seven years, you've done nothing."

What happened in the law-and-order section?

Mr Biden said: "This is a president who has used everything as a dog whistle to try to generate racist hatred, racist division."

Mr Trump countered that Mr Biden, while supporting the 1994 crime bill, had referred to African Americans as "super predators".

The Democrat denied saying such a thing. In 1993, while chairman of the Senate Judiciary Committee, Mr Biden warned of "predators on our streets" who were "beyond the pale".

Mr Trump said: "You can't even say the word 'law enforcement' because if you did say those words you would lose all of your radical left supporters."

In one of the most talked about exchanges of the night, the president was asked by the moderator if he was prepared to condemn white supremacists.

He initially said he would but when asked to denounce the far-right Proud Boys group by name, he sidestepped.

Mr Trump said: "Stand back and stand by, but I'll tell you what, somebody's got to do something about antifa and the left."

What were the ugliest moments?

The feistiest clashes unfolded when the candidates brought up their families.

At one point the president questioned why a company co-founded by his challenger's son, Hunter Biden, had received $3.5m (£2.7m) from a Moscow billionaire, according to a report released by Senate Republicans.

Mr Biden denied the claim, and the two shouted over one another.

As the moderator tried to cut in, the Democrat said: "It's hard to get any word in with this clown. Excuse me, this person."

He added: "I mean, his family we could talk about all night."

Later, Mr Biden referred to claims by anonymous sources that Mr Trump had once called members of the military "losers", a report denied by the president and a number of his former and current aides.

The Democrat angrily said his late son, Beau, who served in Iraq and was awarded the Bronze Star, was not a loser.

"He was not a loser, he was a patriot!" said Mr Biden.

Mr Trump cut in: "Really? Are you talking about Hunter?"

"I'm talking about my son, Beau Biden," said the Democrat.

"I don't know Beau," said Mr Trump. "I know Hunter. Hunter got thrown out of the military. He was thrown out, dishonourably discharged for cocaine use. And he didn't have a job until you became vice-president.

"And once you became vice-president he made a fortune in Ukraine, in China, in Moscow and various other places. He made a fortune and he didn't have a job."

Shouting over Mr Trump, Mr Biden said: "My son, like a lot of people, like a lot of people you know at home, had a drug problem.

"He's overtaken it. He's fixed it. He's worked on it. And I'm proud of him."

Why is the moderator being criticised?

It was Mr Wallace's second time moderating a presidential debate and he at times struggled to rein in the quarrelling rivals.

At one point he urged the president to stop his interruptions.

The Fox News host said: "I think that the country would be better served if we allowed both people to speak with fewer interruptions. I'm appealing to you, sir, to do that."

Mr Trump replied: "Well, and him, too."

Mr Wallace said: "Well, frankly, you've been doing more interrupting."

Mr Trump interjected: "But he does plenty."

BBC