Shocking but not surprising is how we greet the debrief from President Biden’s erstwhile chief of staff, Ron Klain. The disclosures came to the author Chris Whipple in the course of his reporting for an upcoming book. Mr. Klain, a veteran Democratic hand, paints a devastating portrait of the 46th president in twilight. Mr. Biden may be yesterday’s man, but Mr. Klain underscores that the Democrats’ credibility problems are hardly past.

Mr. Klain served as Mr. Biden’s chief aide-de-camp between 2021 and 2023. He then returned to help the president prepare for his disastrous debate against President Trump. Now the Guardian quotes Mr. Klain as reckoning that his boss “didn’t know what Trump had been saying and couldn’t grasp what the back and forth was” and reasoning that NATO leaders “say I’m doing a great job as president so I must be a great president.”

Mr. Klain relates that Mr. Biden “didn’t really understand what his argument was on inflation” and “had nothing to say about a second term other than finish the job.” Mr. Biden at one point hit upon a strategy — if he projected perplexity when Mr. Trump spoke, viewers would conclude that Mr. Trump was an idiot. Mr. Klain replied: “Sir, when you look perplexed, people just think you’re perplexed. And this is our problem in this race.”

Mr. Klain told Mr. Whipple that Mr. 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.” The commander in chief was also apparently “very, very focused on his interactions with NATO leaders” to the extent that Mr. Klain “wondered half-seriously if Biden thought he was president of NATO” instead of America. 

All of this could be water under the bridge — or over the side of the swimming pool — were it not such an astonishing about-face for Mr. Klain, seen as the liberal svengali in Mr. Biden’s circle. In March of 2024 he told the Times that “if I thought he wasn’t the right candidate to beat Donald Trump, I wouldn’t be for him running. But I think he is the right candidate.” Could Mr. Biden’s condition have changed so much in just a couple of months?

Now Mr. Klain tells Mr. Whipple that Mr. Biden was “out of it” before the debate and “out of touch with American politics.” Mr. Klain has in recent days attempted to backtrack, telling the Washington Post that “My point wasn’t that the president lacked mental acuity … He was out of it because he had been [sidelined], not because he lacked capacity.” Sidelining the man in whom all the executive power is vested is its own constitutional scandal. 

Democrats may be buoyant about their results in Tuesday’s special elections. Yet the specter of conspiracy around Mr. Biden’s failings could haunt the party in the midterms and beyond. For all of the chaos swirling around Mr. Trump, a commander in chief who, in Mr. Biden, is unfit to exercise his constitutional duty is a shocking default that Mr. Biden’s camarilla — including Mr. Klain — seems to have aided and abetted.