Biden insists he is staying in presidential race, mixes Harris with Trump

US President Joe Biden mixed up the names of Vice President Kamala Harris and his Republican rival Donald Trump on Thursday but insisted he was pushing ahead with his re-election bid even as more of his fellow Democrats urged him to end his campaign.

"The only thing age does is create a little bit of wisdom if you pay attention," said Biden, who is already the oldest person to ever serve as president.

Since his poor performance against Trump in a presidential debate two weeks ago, Biden has faced growing doubts from donors, supporters, and fellow Democrats about his ability to win the Nov. 5 election and keep up with the demands of the job.

He probably did not help his case when he mixed up his vice president and his Republican rival at the outset of the news conference, which lasted nearly an hour.

"Look, I wouldn't have picked Vice President Trump to be vice president if she was not qualified to be president. So start there," Biden said as he responded to a question from Reuters about his confidence in Harris.

The president coughed frequently and occasionally garbled his responses at the outset of the news conference, and towards the end, his answers frequently trailed off before he had completed his thoughts.

"We must put forth the strongest candidate possible to confront the threat posed by Trump's promised MAGA authoritarianism," he said. "I no longer believe that is Joe Biden."

Biden overcame a childhood stutter and has frequently mangled names and misspoken throughout his political career.

Biden said his health is in good shape and that he would take another neurological exam to determine his mental acuity if his doctors recommended it.

A White House official, speaking on condition of anonymity, told Reuters they did not know whether the news conference would shore up support on Capitol Hill.

Biden donor John Morgan called his performance "fantastic", but another donor, likewise speaking on condition of anonymity, said they did not think it would help, given the heightened scrutiny of Biden's verbal slip-ups.

Biden said he needed to "pace myself" a little more and complained that his aides sometimes overscheduled him. "I'm catching hell from my wife," he said.

Reuters