US President Joe Biden and his Republican rival Donald Trump have traded blows, with the result widely considered a “nightmare” for Biden, in the first televised presidential debate.

There were reports out of the US late on Thursday (local time), after the debate wound up that leading Democrats were considering asking Biden to abandon his re-election campaign after his performance.

“The panic that I am hearing from Democrats is not like anything I have heard,” CNN analyst Abby Phillip said.

“There was a deep frustration about Trump’s lies.”

“Biden’s answers were non-coherent.”

Leading US political website The Hill said one Biden ally described the President’s performance as “an honest-to-God nightmare”.

“I can’t believe what I’m watching. I am watching us lose this election in slow motion,” the unnamed source was quoted as say. Another said it was “political suicide.”

The tightly controlled 90-minute debate wrapped up after Biden and Trump traded attacks on abortion, immigration, the wars in Ukraine and Gaza and their handling of the economy as each sought to shake up what opinion polls show has been a virtually tied race for months.

A hoarse-sounding Biden stumbled over his words several times in the debate’s first half-hour. But he found his footing at the halfway mark when he attacked Trump for his conviction for covering up hush money payments to porn star Stormy Daniels, calling him a “felon”.

In response, Trump brought up the recent conviction of Biden’s son, Hunter, for lying about his drug use to buy a gun.

Moments later, Biden noted that almost all of Trump’s former cabinet members, including former vice-president Mike Pence, had not endorsed his campaign.

“They know him well, they served with him,” he said. “Why are they not endorsing him?”

Two White House officials said Biden had a cold. But his uneven performance could deepen voter concerns that the 81-year-old is too old to serve another four-year term.

I love Joe Biden. I know he’s a good man. I know his heart is good. I know he’s dedicated to our country and is surrounded by good people. Tonight was heartbreaking in many ways. This is a big political moment. There’s panic in the Democratic party. It’s going to be a long night.

— Maria Shriver (@mariashriver) June 28, 2024

Trump, meanwhile, unleashed a barrage of criticisms, including some well-worn falsehoods he has repeated on the campaign trail, such as claims that migrants are behind a crime wave and Democrats support infanticide.

Asked about the January 6, 2021, attack on the US Capitol by a mob of his supporters, the former president refused to accept any responsibility and claimed many of those arrested were innocent.

“This guy has no sense of American democracy,” Biden scoffed in response.

Biden also blamed Trump for enabling the elimination of a nationwide right to abortion by appointing conservatives to the US Supreme Court, an issue that has bedevilled Republicans since 2022.

Trump retorted that Biden would not support any limits on abortions and said the issue should be returned to the states to legislate.

Trump said Biden had failed to secure the southern US border, ushering in scores of criminals.

“I call it Biden migrant crime,” he said.

Biden replied, “Once again, he’s exaggerating, he’s lying.”

Studies show immigrants do not commit crimes at a higher rate than native-born Americans.

Joe Biden lost the country tonight, and will not get it back. If Trump is a threat and democracy is on the line, then Biden must step aside. His duty, oath and legacy require an act of humility and selflessness.

— Steve Schmidt (@SteveSchmidtSES) June 28, 2024

Each called the other the worst president in history; Biden referred to Trump as a “loser” and a “whiner”, while Trump called Biden a “disaster”.

At one point, the rivals bickered over their golf games, with Trump bragging about hitting the ball farther than Biden and Biden retorting that Trump would struggle to carry his own bag.

The televised clash on CNN came far earlier than any modern presidential debate – more than four months before the November 5 election.

The two candidates appeared with no live audience, and their microphones automatically cut off when it was not their turn to speak. Both were atypical rules imposed to avoid the chaos that derailed their first debate in 2020, when Trump interrupted Biden repeatedly.

As the debate began, the two men – who have made little secret of their mutual dislike – did not shake hands or acknowledge one another.

Biden looks and sounds terrible. He looks and sounds so old. So old. Trump is Trump, every word out of his mouth is bullshit. But Biden sounds old. And lost. And that’s going to matter more than anything.

So far, this is an absolute nightmare for Biden.

— Joe Walsh (@WalshFreedom) June 28, 2024

The first questions focused on the economy. Polls show Americans are dissatisfied with Biden’s performance despite wage growth and low unemployment.

Biden acknowledged that inflation had driven prices substantially higher than at the start of his term but said he deserved credit for putting “things back together again” following the coronavirus pandemic.

Trump asserted that he had overseen “the greatest economy in the history of our country” before Covid hit, and said he took action to prevent the economic freefall from deepening even further.

Trump took the stage as a felon who still faces a trio of criminal cases, including over his efforts to overturn the 2020 election.

-with AAP