A new book reveals that an assistant to Vice President Kamala Harris called President Donald Trump a “sociopath” for being nice to Harris on her concession call last November.

Chris Whipple wrote about the story in his book “Uncharted: How Trump Beat Biden, Harris, and the Odds in the Wildest Campaign in History.”

Harris didn’t call Trump on election night, when state after state turned against her. Instead, she waited until the day after the election, when it was clear how badly she had lost.

According to an excerpt in the U.K.’s Daily Mail, Harris told Trump, “I’m calling to concede. It was a fair election. The peaceful transfer of power is important. It’s important to the country.’”

“I hope you’re a president for all Americans,”‘ Harris added, according to the book.

The book said Trump was “bantering as though he were on the golf course.”

Trump told Harris she was “great,” the book said.

“You’re a tough cookie. You were really great. And that Doug — what a character! I love that guy,” the book quoted Trump as saying, referring in part to Doug Emhoff, the former vice president’s husband.

According to the book, a Harris aide was deeply troubled by Trump’s remarks, describing them as “odd and inappropriate.”

“I was like, what?” she recalled, according to the book. “Honestly, I felt like, what is this? It’s so manipulative. He’s a sociopath.”

There were some hiccups with the call’s setup, according to an excerpt in the New York Post.

Whipple wrote that when Harris heard Trump’s voice, she “felt the weight of the crushing defeat.”

According to a book excerpt published by the Guardian, Ron Klain, who served as White House chief of staff under Joe Biden, expressed his disappointment in Biden’s preparations for the disastrous debate he had with Trump in June.

Biden “didn’t know what Trump had been saying and couldn’t grasp what the back and forth was,” the book quoted Klain as saying, noting the former president left debate preparations in favor of a nap by the pool.

Klain was “struck by how out of touch with American politics he was,” the excerpt said.

Klain said Biden was so focused on interacting with NATO leaders that Klain “wondered half-seriously if Biden thought he was president of NATO instead of the U.S.,” the book said.

The book said Biden believed in the debate “If he looked perplexed when Trump talked, voters would understand that Trump was an idiot. Klain replied: ‘Sir, when you look perplexed, people just think you’re perplexed. And this is our problem in this race.’”

While previous reports have said that Nancy Pelosi (D-Calif.) played a major role in upending then-President Joe Biden’s reelection bid, a new book reveals even more details about how far the former House Speaker went in attempting to keep Kamala Harris off the Democratic ticket.

Fox News host Jesse Watters, during his Tuesday show monologue, referenced the new book, “Fight: Inside the Wildest Battle For the White House,” by co-authors Jonathan Allen and Amie Parnes, in which the writers provided additional insight into Pelosi’s behind-the-scenes meddling.