Washington DC - An upcoming book claims that aides to former President Joe Biden weren't trying to cover up his alleged mental decline – they were in denial of it.

In a recent piece for Vanity Fair, reporter Chris Whipple discussed how his new book explores how Biden's administration hid his declining mental state during the 2024 presidential race.

"A cover-up, as we've understood the term to mean since Watergate, involves deliberately hiding something you know to be true," Whipple wrote. "Biden's closest advisers, however, were operating in a fog of delusion and denial; they refused to believe what they could see with their own eyes.

"Despite the president's obvious cognitive decline, they had convinced themselves that he was fine," he continued, adding their denial led to a "political disaster."

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Whipple detailed how prior to Biden's debate with Donald Trump, which led to him dropping out of the race, his chief of staff Ron Klain was "startled," as he'd "never seen Biden so exhausted and out of it."

During one prep session, "Biden suddenly got up, walked out to the pool, collapsed on a lounge chair, and fell sound asleep. Yet his advisers were undaunted."

Klain later told Whipple he was "struck by how out of touch with American politics" Biden appeared to be.

Whipple's book Uncharted: How Trump Beat Biden, Harris, and the Odds in the Wildest Campaign in History will be released in bookstores on Tuesday, April 8.