Adam Schiff reportedly tells donors

The high-profile California Democrat Adam Schiff told donors Joe Biden remaining on top of the ticket for November would cost the party the presidency and probably the House and Senate too, the New York Times reported.

"I think if he is our nominee, I think we lose," Schiff told donors in East Hampton, New York, last Saturday, the paper said, citing "a person with access to a transcription of a recording of the event".

"And we may very, very well lose the Senate and lose our chance to take back the House."

According to the Times, Schiff spoke before Donald Trump, the Republican nominee for president, was shot in the ear in an assassination attempt at a Pennsylvania rally.

As the paper noted, Democratic calls for Biden to stand aside, stoked by concerns about his age and cognitive fitness for office, surged after a disastrous debate with Trump in Atlanta last month but have dropped off since the Trump shooting, in which one rallygoer was killed and two injured.

Nineteen House Democrats and one senator have publicly called for Biden to quit.

Schiff is not among them but he is an influential voice in the party, a former House intelligence chair who led Trump's first impeachment, sat on the January 6 committee and is now a candidate for US Senate.

The Times said the fundraiser was in support of Schiff's Senate campaign and those of Elissa Slotkin (Michigan) and Angela Alsobrooks (Maryland), who both face competitive races.

Schiff did not comment. Biden's campaign told the Times he "maintained strong support from members of Congress".

Biden remains defiant, telling NBC on Monday: "Look, 14 million people voted for me to be the nominee in the Democratic party, OK? I listen to them."

Regardless, Biden's party remains in turmoil.

On Tuesday, Axios reported a move by the Democratic National Committee to conduct a virtual roll call, the process by which the presidential nominee is confirmed, before the party convention in Chicago next month.

Politico then reported a draft letter in which dozens of House Democrats opposed the plan.

The virtual roll call was "a really bad move by the DNC", Jared Huffman, a California Democrat who has not called publicly for Biden to quit, told the site.

"Somebody thinks it's a clever way to lock down debate and I guess by dint of sheer force, achieve unity, but it doesn't work that way."