Defiant Biden pledges victory amid increasing opposition

US President Joe Biden doubled down on his insistence that he will stay in the White House race, despite a growing Democrat revolt that raised speculation he could bow out as soon as this weekend.

“The stakes are high, and the choice is clear. Together, we will win," the 81-year-old said in a written statement from the Delaware beach home where he is recovering from Covid.

Biden vowed to return to the campaign trail next week, and took aim at Donald Trump's "dark" speech accepting his nomination at the Republican National Convention on Thursday.

But his defiance came as six more House Democrats and another senator joined those publicly calling on him to quit November's election out of concerns over slipping polls and worries about his health.

Four of them did so jointly in a letter urging Biden to "pass the torch." Significantly, they included members of the crucial Black and Hispanic caucuses that had so far stayed loyal to him.

Around 25 House Democrats and three senators have now called on Biden to drop out since a disastrous debate performance against Trump and a series of polls showing the Republican on course to win back the White House.

Reports sourced to anonymous sources swirled in US media that Biden was making a plan for a dignified exit in the coming days, accepting warnings from senior Democrats that his time was up.

But his campaign also pushed back, saying that while there had been some "slippage" in support, he was still the best candidate.

"Absolutely the president's in this race," campaign chairwoman Jen O'Malley Dillon told MSNBC's Morning Joe program. "Joe Biden is more committed than ever to beat Donald Trump."

 'Fight on our hands'  

The pressure had mounted dramatically on Thursday with reports that former president Barack Obama, former House speaker Nancy Pelosi and the party's current leaders in the Senate and House had all expressed concerns behind the scenes.

The current House Democratic minority leader, Hakeem Jeffries, was evasive on Friday, saying "it's his decision to make".

"The ticket that exists right now is a ticket we can win on," he told WNYC radio station, adding however that "we have a fight on our hands."

Biden beat Trump in 2020, becoming the oldest president in US history in the process. But as concerns mount over his health, a series of recent polls have shown him trailing Trump in the 2024 race, including in all battleground states that are essential to winning the US electoral college system.

Amid party defections, media speculation is mounting that Biden is using his weekend in Delaware to consult family members and mull over the path ahead.

NBC News reported that some of Biden's family had "discussed what an exit from his campaign might look like" although there was no final decision to do so.

It would involve a "carefully calculated plan" based on his own timing, to give some dignity to what would be a historically late decision by a sitting US president not to run.

Any decision by Biden to step aside less than four months from the November 5 election would also have to try to avoid chaos in the Democratic party over his successor as nominee.

The frontrunner would be Vice President Kamala Harris, whose prospects in a match-up with Trump have been quietly gamed by campaign officials as the crisis around Biden grew.

The split-screen has been particularly stark as Trump gave a triumphant speech at the Republican convention in Milwaukee on Thursday, just days after surviving an assassination bid.