'Recklessness': Kamala Harris turns on Joe Biden in new book

"Their thinking was zero-sum: If she’s shining, he’s dimmed," Harris said.

Former Vice President Kamala Harris says that Democrats made a mistake and it was "recklessness" to allow President Joe Biden to make the decision alone on running for reelection, saying the choice should not have been "left to an individual’s ego.”

In an excerpt from her forthcoming book, "107 Days," published in The Atlantic Wednesday morning, Harris, in a remarkable turnaround, said "as loyal as I am to President Biden, I am more loyal to my country," and lamented her time in Biden’s administration, saying "getting anything positive said about my work or any defense against untrue attacks was almost impossible."

Harris said the president’s staff fueled negative stories about her performance as vice president and often refused to defend her against attacks against Republicans, including the narrative that she had a "chaotic" office and unusually high staff turnover during her first year.

"I was the first vice president to have a dedicated press pool tracking my every public move," Harris said. "Before me, vice presidents had what’s called a ‘supplemental pool," as the first lady does, covering important events. Because of this constant attention, things that had never been especially newsworthy about the vice president were suddenly reported and scrutinized."

At another point in the excerpt, Harris defended Biden, dismissing those who say he was incapable of serving as president.

ABC News has reached out to the Biden camp for comment.

In May, Biden, in a wide-ranging interview on ABC's "The View,” said he was not surprised by Harris' loss in the 2024 presidential election, but not because of her qualifications as a candidate -- instead, pointing to what he said was sexism and racism leveled against her.

"I wasn't surprised, not because I didn't think the vice president was the most qualified person to be president … I wasn't surprised because they went the route of -- the sexist route, the whole route," Biden said.

But Biden, separately in the same interview, said he still thinks he would have beaten Trump if he had stayed in the race.

"Yeah, he still got seven million fewer votes," Biden said of Trump, noting by how much he beat Trump in the 2020 election popular vote.

When asked to respond to claims that he should have dropped out of the race and endorse Harris sooner, Biden said in the interview that Harris still had a long period to campaign and that they worked together "in every decision I made."

Biden also denied reporting that claimed he had advised Harris to suggest that there was no daylight between the two of them -- saying that they were partners and worked together.

Harris, however, now sees this slightly differently.

"When the stories were unfair or inaccurate, the president’s inner circle seemed fine with it,” Harris said in the excerpt from her book. “Indeed, it seemed as if they decided I should be knocked down a little bit more."

"Their thinking was zero-sum: If she’s shining, he’s dimmed," Harris said. “None of them grasped that if I did well, he did well. That given the concerns about his age, my visible success as his vice president was vital. It would serve as a testament to his judgment in choosing me and reassurance that if something happened, the country was in good hands. My success was important for him."

"His team didn’t get it," Harris said.