Trump once called Sessions “mentally retarded” and a “dumb Southerner”

President Donald Trump reportedly once became so enraged with Attorney General Jeff Sessions that he mocked his Southern accent and called him “mentally retarded.”

“He’s this dumb Southerner,” Trump reportedly told former staff secretary Rob Porter. “He couldn’t even be a one-person country lawyer down in Alabama.”

The anecdote is recounted in Bob Woodward’s forthcoming book Fear, which contains hundreds of interviews with firsthand witnesses in the White House and other sources that participated in the reporting on “deep background,” according to the Washington Post.

While the president is the best documentarian of his own petulance, often firing off early-morning tweet storms featuring childish nicknames to impugn his political foes, Woodward’s book details dozens of other previously unreported instances of what he refers to as a “nervous breakdown” of the executive branch.

In addition to his near-relentless attacks on Sessions — who Trump reportedly referred to as a “traitor” after he recused himself from special counsel Robert Mueller’s investigation into Russian collusion — the president also reserved choice barbs for other high-ranking members of his cabinet. In once instance, he told Porter to ignore former chief of staff Reince Priebus because he was “like a little rat,” and in another, he complained former national security adviser H.R. McMaster dressed in cheap suits, “like a beer salesman.”

More concerning than the president’s petty insults is the general esteem in which he seems to be held by the majority of his inner circle.

According to Woodward, White House chief of staff John Kelly once told colleagues the president is “unhinged” and “an idiot,” during a group meeting Trump was not present for.

“It’s pointless to try to convince him of anything,” Kelly reportedly told a small group of advisers. “He’s gone off the rails. We’re in Crazytown. I don’t even know why any of us are here. This is the worst job I’ve ever had.”

During a Jan. 19 meeting of the National Security Council, Woodward reports, Defense Secretary Jim Mattis was once forced to frustratedly explain that U.S. spending on military resources in North Korea was justified because “we’re doing this in order to prevent World War III.” After Trump left the room, Mattis reportedly told others present that the president “had the understanding of — ‘a fifth- or sixth-grader.’”

Also outlined in the book are the covert ways White House staffers have attempted to stave off disaster brought on by the president’s mercurial temperament, including a plot to ferry important documents out of the Oval Office so Trump would not see them and become enraged.

Fear is expected to hit shelves Sept. 11.