One of Biden's most faithful allies appears ready to break

• Biden's union allies are questioning his candidacy, according to The Washington Post.
• The publication said union leaders want Biden to spell out his plan for beating Trump.

Joe Biden this week described himself as the most pro-union president in US history.

"I think of you as my domestic NATO — not a joke," the president said during a speech on Wednesday to the executive council of the AFL-CIO, America's largest federation of trade unions.

Biden regularly plays up his support from unions, and he may just be counting on it for his survival.

But that support could be about to break.

According to The Washington Post, top union leaders have privately expressed concerns about Biden's ability to beat Trump in November.

The Post, citing two anonymous sources familiar with the comments, said union leaders repeatedly asked Biden campaign officials for their plan on how to defeat Trump in a closed-door meeting on Wednesday.

The report said Sara Nelson, president of the Association of Flight Attendants, and Shawn Fain, president of the United Auto Workers, were among the most outspoken attendees.

The Association of Flight Attendants and the United Auto Workers did not immediately reply to a request by Business Insider for comment.

More members of Biden's senior campaign staff are also beginning to doubt his future, the Post said.

"Overwhelmingly a majority of senior campaign staff are despondent and don't see a path," a Democratic strategist familiar with the conversations told the publication.

For now, union leaders are continuing to publicly support the president. In a statement Wednesday, AFL-CIO leadership said it had "unanimously voted to reaffirm its commitment," adding that "no president has been more invested in helping workers than Joe Biden."

United Steelworkers International President David McCall said before Wednesday's meeting that his union "proudly supports" Biden and that his "record of delivering for working people stands for itself."

Losing support from labor

According to Politico's Jonathan Martin, support from the unions is likely Biden's only path to survival against Trump.

Just days ago, Anita Dunn, Biden's longtime advisor, told Politico: "The people Joe Biden fights for — middle-class labor union members, Blacks, Latinos — they know he fights for them, and they're going to stay in the fight for him."

Biden and other Democrats have regularly touted the president's pro-labor credentials.

The AFL-CIO told the Associated Press on Thursday that Biden's "fighting spirit" was on full display during his meeting with union leaders this week.

The AP noted that some statements of support were worded diplomatically in case Biden caves in to pressure to drop out.

That pressure is growing after Biden's disastrous performance in the June 27 presidential debate against Trump, which has raised questions about his age and mental agility.

CBS/YouGov poll on June 30 found that 72% of registered voters believe Biden does not have the mental and cognitive health to be president, while reports say that behind closed doors, Biden has also shown signs of aging, including fumbling remarks and appearing forgetful at a recent D-Day event with world leaders

Sen. Peter Welch of Vermont, in an op-ed in the Post on Wednesday, became the first Democratic senator to call on Biden to step aside, saying it was "for the good of the country."

Hollywood actor and Democratic supporter George Clooney, in an op-ed in The New York Times, said that the Biden he met at a fundraising event three weeks ago wasn't the Joe Biden of 2010.

He "wasn't even the Joe Biden of 2020," said Clooney."He was the same man we all witnessed at the debate."

Meanwhile, Senate Majority Leader Chuck Schumer privately told donors he's open to replacing Biden as the party's presidential nominee, Axios reported, citing three unnamed sources familiar with the matter.

And on Wednesday, Nancy Pelosi, who stepped down as speaker early last year, failed to clearly endorse Biden as the Democratic candidate.

If union leaders join the chorus of voices asking Biden to step down, other key supporters may quickly follow.