Anyone with eyes knew that President Joe Biden was in a sharp decline, health-wise. Even his own people knew it, though they worked overtime to pretend it wasn't happening.

But that's starting to change, as it was revealed by the Daily Caller that one of President Biden's top former aides just admitted in a new book that it was well known within the White House just how bad the elderly president was getting.

Former top aide Ron Klain wrote that he believes Biden wasn't grasping the back-and-forth debate prep before his disastrous debate with Donald Trump, ultimately leading to his ouster from the race.

Klain also admitted that Biden would fall asleep by the pool during their debate prep.

What did he say?

The situation was so bad that Klain reportedly thought that Biden was "half-seriously" wondering if President Biden believed he was the president of NATO rather than the United States president.

The information was revealed in excerpts from Chris Whipple's new book, which were published by The Guardian.

The Daily Caller noted:

While they prepped, Klain reportedly told Whipple that the then 81-year-old president “didn’t know what Trump had been saying and couldn’t grasp what the back and forth was” and would have to cut training sessions short because he was tired.

The debate prep went so horribly bad that a 90-minute prep session was called off as Biden reportedly not grasping domestic policy, the book noted.

The Daily Caller added:

As the former president became irritable, Klain pushed Biden to run on “unfinished business” and his attempt to “subsidize state and local efforts to do childcare and bring down the cost to $20 a day. And you ought to try to fight for it again,” according to the excerpt.

The book noted that after Klain attempted to explain simple concepts regarding domestic policy, Biden admitted that he was "tired."

“‘I’m just too tired to continue and I’m afraid of losing my voice here and I feel bad,’ [Biden] said. ‘I just need some sleep. I’ll be fine tomorrow.’ He went off to bed,” Whipple added in the book.

Out of touch

Whipple wrote that Klain was somewhat taken aback by how "out of touch" Biden seemed regarding the American people.

"At his first meeting with Biden in Aspen Lodge, the president’s cabin," Whipple wrote, Klain "was startled. He’d never seen him so exhausted and out of it. Biden was unaware of what was happening in his own campaign. Halfway through the session, the president excused himself and went off to sit by the pool."

Klain is the first high-profile former Biden aide to finally admit that the situation was far worse than their media allies attempted to hide. Only time will tell if more former Biden staffers follow suit.