Democrats who are pushing presumptive presidential nominee Joe Biden to skip this fall's debates against Donald Trump are revealing a lack of confidence in the candidate, former White House press secretary Ari Fleischer told “Outnumbered Overtime” on Monday.

"Have you ever seen the Democrats so fearful that they need to bubble wrap their candidate because they don’t think he can stand on the stage for an hour and a half or two hours?" Fleischer asked. "Of course there have to be debates. The American people will demand them."

Fleischer was responding to one of his predecessors as White House press secretary, Joe Lockhart, who penned an op-ed last week urging Biden not to debate Trump prior to the November election.

CLINTON EX- SPOX URGES BIDEN TO SKIP PRESIDENTIAL DEBATES

“Whatever you do, don’t debate Trump,” Lockhart wrote on CNN's website. “Trump has made more than 20,000 misleading or false statements according to the Washington Post. It’s a fool’s errand to enter the ring with someone who can’t follow the rules or the truth. Biden will undoubtedly take heat from Republicans and the media for skipping the debates. But it’s worth the risk as trying to debate someone incapable of telling the truth is an impossible contest to win.”

Fleischer argued that a Biden cancellation would raise more questions about the former vice president's fitness for office, and compared the move to an incident in 2016 when Hillary Clinton appeared to stagger and faint during a 9/11 memorial event in New York City.

"Remember when the video showed Hillary Clinton collapse and getting into a car? Everybody saw it and we all wondered, 'Is she OK?' That should be at the equivalent if he doesn’t show up on the stage," Fleischer said.

"He only campaigned once or twice a day in the primaries, while other Democrats had the vigor to have four or five events a day," he went on. "Joe Biden was only able to muster the strength to have one or two a day ... it’s hard to run for president, it’s hard to be president.

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"If he fails to take the stage, that [will] only reinforce questions about if he’s too weak," Fleischer continued. "Does he lack the vigor to be the president of the United States? That’s why I think this is a nonstarter for Joe Biden."

Trump supporters have poked fun at the former vice president for conducting many interviews from his Delaware basement and only making a handful of in-person appearances.

"The stakes will be higher, because nobody has really seen Joe Biden out on the stump," Fleischer said. "People really are going to tune into the debates and see how he is. Is he OK?"

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Biden's deputy campaign manager and communications director Kate Bedingfield told “America’s Newsroom” later Monday that Biden is “very much looking forward to debating Donald Trump,” and argued that the Biden campaign has already agreed to the upcoming three presidential debates, while the Trump campaign has not.

“I would say there is one candidate in this race who has agreed to three debates and that’s Joe Biden," Bedingfield said. "The Trump campaign has actually not agreed yet to participate in the debates set by the presidential debate commission."

Fox News' Edmund DeMarche and Talia Kaplan contributed to this report.