WASHINGTON (TNND) — Explosive revelations about former President Joe Biden's health during his last two years in office include a story that those in the former president's inner circle considered putting him in a wheelchair.

It's one of the details set to emerge in an upcoming book, "Original Sin: President Biden's Decline, Its Cover-Up, and His Disastrous Choice to Run Again," co-authored by Axios reporter Alex Thompson and CNN Anchor Jake Tapper. The book alleges that Biden's decline was far more severe than the public was led to believe.

According to the book, had Biden continued his campaign and won re-election, his aides were reportedly considering the use of a wheelchair due to his deteriorating condition.

The book describes incidents such as a fall in 2023 that prompted aides to take measures to prevent further tripping mishaps, noting that his condition was evident in his gait. They reportedly shortened or changed routes he'd take around the White House and at events. The use of a wheelchair was not considered an option until after the election.

Biden's disastrous debate performance in the summer of 2024 made many Americans grow more skeptical about the president's ability to continue doing the job. Meanwhile, the White House consistently maintained that Biden was mentally sharp.

He is as sharp as ever, as I’ve known him to be, in my engagement, in my experience with him," former White House Press Secretary Karine Jean-Pierre told reporters during a briefing on July 3, 2024.

Biden addressed the questions about his fitness during his first American post-presidential interview on "The View" last week.

"They are wrong. There’s nothing to sustain that," he said when asked about the sources making the claims. "The only reason I got out of the race is because I didn’t want to have a divided Democratic party."

The book also suggests that concerns about Biden's abilities eventually alarmed donors and supporters, leading to his withdrawal from the race, his endorsement of then-Vice President Kamala Harris, and ultimately a victory for Donald Trump. Some Democrats who supported Biden at the time are now facing scrutiny over their public statements compared to their private observations.

Sen. Elizabeth Warren, D-Mass., hesitated as she answered questions about it on the "Talk Easy with Sam Fragoso" podcast last month.

I said what I believed to be true," she said.

And when asked if she thought Biden was as sharp as she was, she replied, "Um, I said I had not seen decline."

The book draws on accounts from 200 sources, with some media members now acknowledging that Biden's decline was a significant story that was underreported and overlooked in real time. A Biden spokesperson told Axios in part, "Yes, there were physical changes as he got older, but evidence of aging is not evidence of mental incapacity."