While both campaigns declared victory after the 90-minute debate, most observers — including many Republicans — said Ms Harris was the clear winner, repeatedly baiting the former President into angry, rambling answers.

Mr Trump’s probability of winning the November 5 election dropped 3 per cent after the debate, according to Polymarket, which now has the candidates tied at 49 per cent.

In a poll of CNN viewers after the debate, 63 per cent said Ms Harris won while 37 per cent said Mr Trump won. The same group had been split 50-50 on who they expected to win going in.

A poll by Trafalgar, which tends to lean more Republican, also gave the debate to the Democrat by 55 per cent to 43 per cent.

Tellingly, the Harris campaign immediately called for a second debate.

Speaking in the “spin room” shortly afterwards, Mr Trump claimed “it was my best debate ever, I think”.

“Now, she wants to do another one, because she got beaten tonight,” he said. “But I don’t know if we’re going to do another one. I wouldn’t mind.”

He added, “I thought the moderators were very unfair. Basically it was three-on-one. But I thought they were very unfair. I assumed the moderators would be bad because that is the worst of the networks, in my opinion.”

The Trump camp issued a statement as the debate neared its conclusion claiming victory.

“President Trump delivered a masterful debate performance tonight, prosecuting Kamala Harris’ abysmal record of failure that has hurt Americans for the last four years,” campaign managers Chris LaCivita and Susie Wiles said.

“We saw President Trump lay out his bold vision of America and how he would continue to build upon the successes of his first term by supercharging the economy, securing the border, and stopping crime from ravaging communities across the country.

“Conversely, Kamala’s vision of America was a dark reminder of the oppressive, big government policies of Joe Biden that she wants to continue. High inflation, a porous border that allows criminals and terrorists to flood across, and being soft on crime — that is what Kamala represents.

“The choice could not be more clear — President Trump was the clear winner tonight, and he will win for America when he returns to the White House.”

The Harris campaign also issued a statement declaring victory.

“Tonight, Vice President Harris commanded the stage on every single issue that matters to the American people,” said Harris campaign chair Jen O’Malley Dillon.

“Americans saw exactly what kind of President Kamala Harris will be — one who offers a New Way Forward for the country, who will be a president for all Americans, and who will turn the page once and for all on the darkness and division of Donald Trump. And she reminded the American people that she is the only candidate in this race ready to serve as our next Commander-in-Chief.

“Donald Trump was totally incoherent. He was angry and rattled, and it all began when Vice President Harris held him accountable for his record overturning Roe v. Wade and harming women nationwide.

“Under the bright lights, the American people got to see the choice they will face this fall at the ballot box — between moving forward with Kamala Harris, or going backwards with Trump. That’s what they saw tonight and what they should see at a second debate in October.

“Vice President Harris is ready for a second debate. Is Donald Trump?”