Some of the nation’s top business and labor leaders voiced alarm in the hours following the presidential debate on Thursday night, as some raised concern about President Joe Biden’s age and others questioned former President Donald Trump’s fitness for office.

Prominent figures who already held misgivings about Biden seized on his debate performance and doubt whether Biden can handle the demands of a second term. Even allies of Biden stopped short of praising his performance, including some who entertained the possibility of replacing Biden at the top of the Democratic ticket.

Some leaders of companies and labor unions, on the other hand, sharply criticized a dearth of policy and a stream of falsehoods issued by Trump during the 90-minute event. Among them, some reaffirmed their support for Biden.

Billionaire entrepreneur Mark Cuban, who attended a Biden fundraiser in March, said in a statement on X that both candidates performed poorly. The display elicited enough worry about Biden that Cuban is now open to a discussion about him stepping aside, Cuban added, noting that he would vote for Biden if he remains the nominee.

“His performance was awful. But so was Trump’s,” Cuban said. “Biden was feeble. Trump couldn’t directly answer a single question.”

The Biden campaign did not immediately respond to a request for comment from ABC News. Neither did the Trump campaign.

Within 10 minutes of the start of the debate, Biden-friendly CEOs began sending panicked emails and text messages, Jeffrey Sonnenfeld, a professor at Yale University who keeps close contact with executives, told ABC News.

Some CEOs, who had spoken with Biden as recently as last month at a fundraiser in Greenwich, Connecticut, felt “completely weirded out” watching a candidate who appeared much less capable, Sonnenfeld said.

In all, Sonnenfeld said he has heard alarm from about 30 CEOs at private and public companies since the debate, saying they’ve used terms like “fear, nausea and distress” in response to Biden’s performance.

More than half of the CEOs said that Biden should end his presidential campaign and allow another Democrat to run, Sonnenfeld said, noting that the urgency among them was fueled in part by “revulsion toward Trump.”

“They were so horrified by the force and volume of Trump’s demonstrable lies,” Sonnenfeld said. “That only intensified their hostility toward the prospect of a second Trump candidacy.”

Meanwhile, some Trump supporters across Silicon Valley and Wall Street said Biden’s performance reaffirmed their allegiance.

“Tonight was an indictment of the Democratic Party,” Bill Ackman, a billionaire hedge fund manager, said on X. “How could they? Did they think they could pull one over on the American people?”

David Saks, a high-profile venture capitalist who has endorsed Trump, similarly questioned Biden’s capacity in a post on X.

“If Biden can’t handle a debate, how can he handle the most dangerous foreign policy situation since the Cuban Missile Crisis?” Saks said. “It’s time to pull back from the brink.”

By contrast, labor leaders supportive of Biden stopped short of praising his debate performance but emphasized the shortcomings of Trump.

“Donald Trump once again showed himself to be a scab, a liar, and a billionaire who will never stand with the working class,” Shawn Fain, the president of the United Autoworkers, which has endorsed Biden, told ABC News in a statement.

Randi Weingarten, the president of the American Federation of Teachers, which also endorsed Biden, echoed such criticism of Trump.

“Joe Biden’s performance might not have matched his performance as president, but he tried to get the facts out and lay down his vision for the country — while Donald Trump told the same lies over and over and was rarely held to account by the moderators,” Weingarten said.

On the campaign trail, Biden and Trump have promoted competing agendas for the U.S. economy.

Biden has vowed to raise taxes on large corporations and wealthy people, while Trump has promised to renew a tax cut measure from his first term in an effort to spur economic activity.

Trump has frequently criticized Biden for the nation’s yearslong bout of elevated inflation. For his part, Biden has acknowledged that price increases remain too high but he has touted significant progress in bringing inflation down well below its peak.

In the aftermath of the debate, many prominent CEOs and labor leaders opted to forego public statements.

Dean Phillips, an entrepreneur and an opponent of Biden in the Democratic primary, drew attention to his own muted response.

“Speak only if it improves upon the silence,” Phillips said in a post on X, attributing the phrase to anti-colonial Indian leader Mahatma Gandhi.