Journalist Edward-Isaac Dovere talked about his new book, Battle for the Soul: Inside the Democrats’ Campaigns to Defeat Trump, with late-night talk show host Seth Meyers on Thursday.

Dovere’s book chronicles the Democratic primaries of 2020, which culminated in the ultimate success of the Biden-Harris ticket. In a starred review, a critic for Kirkus called the book “a wide-ranging history of a tangled campaign—catnip for politics junkies.”

Meyers asked if Dovere was surprised that Joe Biden picked Kamala Harris for the No. 2 slot after the first Democratic primary debate, which led to bad blood between the two.

“You go back to that first primary debate where she went after him, said, ‘I believe you’re not a racist,’ and then really just clotheslined him about his record on busing,” Dovere said. “And I report in the book that Biden standing on stage was so annoyed about what happened that he turns to Pete Buttigieg standing next to him, and says, ‘Well, that was some fucking bullshit.’”

First lady Jill Biden was also none too pleased with Harris’ attack on the now-president, Dovere said.

“Jill Biden was on a phone call with some supporters a little bit after the debate, and she was so mad. She said, ‘With the life that he’s led, the work that he’s done, to stand up there and you call him a racist? Go fuck yourself.’”

Dovere recalled a phone conversation he had with Biden not long after his inauguration, in which he asked the president whether he’s gotten used to being in the Oval Office and waking up upstairs. Biden joked that nobody told him that moving was part of the gig.

“I said, ‘Well, you’re the one who wanted this job,’” Dovere said. “And he said to me, ‘You know, someone said to me, I’m like the dog that caught the car after running for so long. No, I caught the bus. I’m the dog that caught the bus.’”

Michael Schaub is a Texas-based journalist and regular contributor to NPR.