"The debate was President Biden’s chance to disrupt the narrative that he’s too old and reset the terms of the race. This failed miserably. It validated years of rightwing attacks on Biden and made clear he is incapable of prosecuting the case," the document continued. "His debate performance, the campaign’s defensive response, and the total lack of plan to reassure his base and the voters about his capability should shake everyone’s confidence that he can win this election. Failure will have devastating results for our democracy."

The memo, which is freely available to view online, notes that it is "intended for Democratic party stakeholders - activists, donors, electeds, commentators, etc - who are concerned about our current trajectory but unclear about what should happen or what to do." It lays out three scenarios: Either Biden can take steps to alleviate concerns about his cognitive health with regular public appearances, Harris or another Democrat instead becomes the nominee, or Trump wins the election.

"Ultimately only Joe Biden has the power to drop out and to choose to head off chaos by anointing Harris, but he listens to people, and they listen to people, and you might know those people," the authors wrote. "If so, and if you find this convincing, you should make this case."

The identity of the authors remains unknown, but the memo states that those behind the document are "senior operatives within Democratic political institutions that will not be taking a position regarding this crisis" with "no professional or personal ties to Harris" who "simply want to defeat Trump."

"Right now, the most important thing to do is to make noise in support of this basic premise: Kamala is the only viable option to succeed Biden, and if she gets the nomination, she can win," the document read.

The document's popularity among Democratic donors suggests that Biden has done little since the debate to assuage fears that the candidate they're financially supporting is up to the task of defeating Trump and holding the White House for another four years. Even though Biden has vowed repeatedly to stay in the race — including as recently as Friday during a rally in the battleground state of Wisconsin — he's lost faith among elected Democrats both in Congress and in statehouses.

Massachusetts Governor Maura Healey (D) stated Friday that Biden should "listen to the American people," urging him to reconsider his promise to stay on the ticket through November. And a group of Senate Democrats led by Senate Intelligence Committee chairman Mark Warner (D-VA) are planning to formally ask Biden to step aside from his campaign next week.