WASHINGTON, Sept. 29 (Xinhua) -- The first 2020 U.S. presidential debate descended into chaos on Tuesday night as President Donald Trump and his Democratic challenger, Joe Biden, clashed fiercely.

In Cleveland, Ohio, the candidates shared their views on a series of issues, including Supreme Court, health care, COVID-19, economy, climate change, protests and violence in U.S. cities, integrity of the election, and their records.

However, heated exchanges and personal attacks bulldozed the 90-minute-plus debate, as Trump appeared intended to interrupt Biden on nearly every topic, while the former U.S. vice president called his opponent a "liar" and a "clown" and told him to "shut up."

"Gentlemen! I hate to raise my voice," moderator and Fox News anchor Chris Wallace, who had to frequently intervene, said at one time. "I think that the country would be better served if we allowed both people to speak with fewer interruptions."

The veteran journalist opened the debate by asking Trump to explain his nomination of conservative federal appellate judge Amy Coney Barrett for the Supreme Court only weeks before the November election despite strong pushback from Democrats.

"I will tell you very simply, we won the election. Elections have consequences," Trump said. "We have the Senate, we have the White House and we have a phenomenal nominee respected by all top top academic good in every way, good in every way."

Biden, for his part, said that he believes Barrett "seems like a very fine person" but argued that "the election has already started," referring to early voting, either in-person or by mail, in some states, and that whoever wins it should pick the replacement for the late Supreme Court Justice Ruth Bader Ginsburg, a liberal icon.

"Tens of thousands of people have already voted. The thing that should happen is, we should wait," the former U.S. vice president said. "We should wait and see what the outcome of this election is."

He sought to tie the nomination to Trump's years-long efforts to repeal Obamacare, or the Affordable Care Act, a comprehensive health care reform law enacted by then-President Barack Obama in 2010.

"The president has made it clear he wants to get rid of the Affordable Care Act ... which will strip 20 million people from having insurance," Biden said. "He's been running on that, he ran on that, and he's been governing on that."

Trump has long criticized costs and coverage under Obamacare and has vowed to repeal and replace it since his 2016 campaign. Supporters of Obamacare have noted Barrett's past criticism of Supreme Court ruling in 2012 upholding the law and argued that her presence at the high court, where conservatives are poised to have a bigger majority, could put it at risk.

"It's a disaster. It's too expensive. Premiums are too high. That it doesn't work. We do want to get rid of it," Trump said on Tuesday night, while touting his own health care proposals, which Biden called "wishful thinking."

Wallace also asked Trump to respond to a recent New York Times investigation which alleged that he paid just 750 dollars in federal income tax in both 2016 and 2017 and paid no taxes in 10 of the previous 15 years.

"I paid millions of dollars in taxes, millions of dollars of income tax," Trump said. As the Republican continued to speak, Biden interrupted, saying "show us your tax returns."

"Chris, let me tell you something, I don't want to pay tax," Trump continued. "Like every other private business person, unless they're stupid, they go through the laws."

Hours earlier, Biden released his tax returns from 2016 to 2019, to seize upon the Times investigation. Over the past several months, he has emphasized the "Scranton vs. Park Avenue" message to appeal to working-class voters, which points to his Pennsylvania boyhood home and Trump's adult life in Manhattan, New York City.

A former business mogul, Trump has refused to release his tax returns, which are being sought by Democrats and state investigators, during his presidency, breaking a decades-old tradition maintained by his predecessors.

A CBS News instant poll on Tuesday night showed 48 percent of viewers thought Biden won the presidential debate, and 41 percent favored Trump. Another 10 percent said they believed it was a tie.

"It was a contentious debate with lots of interruptions and personal attacks by each candidate. Yet there also was considerable discussion of the issues," Darrell West, vice president and director of Governance Studies at Washington, D.C.-based think tank Brookings Institution, told Xinhua.

"On the whole, Biden had clear and in-depth answers that should reassure voters he is up to the job of being president," West said. "Trump created a caricature of an incompetent Biden but the former vice president was on top of the issues and pointed out his substantive differences with his opponent."

Earlier CBS News polling showed that the vast majority of likely voters planning to watch the debate had already decided on their candidate. Christopher Galdieri, a political science professor at Saint Anselm College in New Hampshire, said that he doubts the debate "will have much impact" and that "generally speaking debate audiences tune in to see how their candidate does, rather than to make up their minds."

Trump and Biden will have two more debates in October leading up to Election Day. The Biden campaign said the Democrat will attend the events despite the chaos of the first face-off.

"Joe Biden's gonna show up," Kate Bedingfield, Biden's deputy campaign manager and communications director, said in a post-debate press call. "The next debate is a town hall format where real voters are going to have the chance to engage the candidate. Biden obviously relishes any opportunity to talk directly to real voters, that's something that he prioritizes doing on the campaign trail."

Trump will hit the campaign trail on Wednesday by visiting Minnesota, a state he hopes to flip.

Election Day falls on Nov. 3 this year. According to the RealClearPolitics polling average, Biden leads Trump by 6.1 percentage points nationally and 3.5 points in top battleground states, as of Tuesday.