New book reveals Biden's inner circle worried about his age years before botched debate performance

A new book about President Joe Biden's cognitive decline and his administration's alleged cover-up has forced a reckoning in the Democratic Party. 

Biden's aides worried about his age long before his consequential 2024 presidential debate against then-former President Donald Trump, CNN anchor Jake Tapper and Axios political correspondent Alex Thompson reveal in their book, "Original Sin: President Biden’s Decline, Its Cover-Up, and His Disastrous Choice to Run Again," which was released on Tuesday.

"During an eight-day, grueling bus tour in Iowa in December 2019, Biden gave his aides pause. While doing prep, he struggled to remember the name of longtime aide Mike Donilon. ‘You know, you know,’ he said, groping for it. His aides side-eyed one another–Donilon had worked for Biden since 1981," Tapper and Thompson wrote. 

That was not the only time aides worried about Biden on the 2020 presidential campaign trail, according to the book. The journalists described aides "white-knuckling" through debate performances as they "shied away from tough interviews" because Biden no longer communicated the way he did as senator or vice president. 

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The book details his aides' concerns on the 2020 campaign trail that voters in battleground states were seeing a "diminished man" who was "not always 100 percent" during the relentless campaign schedule. 

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Without the COVID-19 pandemic, his aides "doubted Biden could have otherwise kept up the pace of campaigning through November."

However, even during the pandemic, Tapper and Thompson described Biden as struggling to stay on message as his aides tried to soften his blunders. Two aides who grew closer to Biden during lockdown, Annie Tomasini and Anthony Bernal, "loaded a written Q&A into a prompter ahead of a local interview – a document that the campaign had used in prep with Biden," according to the book. 

"The team was constantly trying to change the Zoom configurations and production designs to adapt to him. Aides privately noted that they couldn't rely on him to stay on message, and he often had a very short attention span."

Tapper and Thompson describe a turning point during the 2020 campaign when Biden struggled to follow virtual conversations with American voters through a series of monitors for the Democratic National Convention. 

"It was like a different person. It was incredible. This was like watching Grandpa who shouldn't be driving," one Democrat told the journalists. 

After watching the short, overly edited videos of Biden struggling to interact with voters, Democrats told Tapper and Thompson that they did not think Biden could be president. They said Democrats became angry imagining his aides seeing him like this every day. 

A Biden spokesperson, however, pushed back on the narrative of the book, telling Fox News Digital that "there is nothing in this book that shows Joe Biden failed to do his job, as the authors have alleged, nor did they prove their allegation that there was a cover-up or conspiracy."

"Nowhere do they show that our national security was threatened or where the President wasn’t otherwise engaged in the important matters of the Presidency," the spokesperson continued. "In fact, Joe Biden was an effective President who led our country with empathy and skill."

However, those close to Biden told Tapper and Thompson that the "first signs he was deteriorating emerged after the death of his beloved son Beau in 2015."

"Beau's cancer treatment also demonstrated the Bidens' capacity for denial and the lengths they would go through to avoid transparency about health issues, even when the person in question is an elected official, in this case the sitting attorney general of Delaware."

Tapper and Thompson described how the Biden family went through great lengths to downplay or mislead the media about then-vice president Biden visiting his son in the hospital. 

"Beau's wife, Hallie, told people she didn't understand why they had to keep his illness a secret."

Fox News Digital has written extensively dating back to the 2020 presidential campaign about Biden's cognitive decline and his inner circle’s role in covering it up.