Former Vice President Kamala Harris pleaded with former President Biden to endorse her White House bid on the same day as his historic move to end his 2024 reelection bid, according to exclusive excerpts from a forthcoming book. 

“You need to endorse me,” Harris begged Biden in the moments before the ticket switch-up, as reported by The Hill’s Amie Parnes and NBC News’s Jonathan Allen in excerpts from “Fight: Inside the Wildest Battle for the White House,” which is set for release Tuesday. 

Harris, who would face a short runway to build momentum before the November election, knew she had Biden’s support to take up the torch. But she wanted to avoid a bigger gap between his exit and his endorsement, which could have created an opening for a messy contested nomination fight as some key figures in the party hoped to pass her over. 

“She knew that if Biden stepped aside without explicitly backing her, it would be taken as a statement that he lacked confidence in her ability to win or to do the job­ or both,” according to the book. “That could mean crib death for a battle that she had not yet begun to fight. She also knew that a failure to throw his weight behind her would suggest that he had made the wrong decision in choosing her as his number two in the first place.”

According to Parnes and Allen, Biden called Harris in the hours before his exit to share his plans and, after checking whether the president was sure of his decision, she stressed the importance of timing his exit and endorsement together. 

Harris told her then-boss that “this is important for your legacy to show that you have absolute faith in your VP.” When Biden suggested waiting a couple of days after his exit announcement to make the endorsement, Harris said “too much daylight” would risk “mischief and confusion.”

When Biden ran his statement by Rep. James Clyburn, the South Carolina Democrat said “there’s something missing” and stressed the president couldn’t “leave the field without endorsing a successor,” Parnes and Allen reported.

Clyburn, whose 2020 endorsement boosted Biden’s primary momentum, wanted to rally support for Harris, but he was reportedly aware that some other top Democrats including former Speaker Nancy Pelosi (D-Calif.), former President Obama and some major donors wanted to keep her from the nomination.

Clyburn, like Harris, was anxious about whether the timing of Biden’s endorsement could leave room for others in the party to try to take his place as the party’s nominee, and he stressed party unity in a phone call with Obama scheduled for later the same day Biden gave him a heads-up on his exit.

“’Obama’s going to try to rope me into some kind of mini-­ primary,’ Clyburn thought. ‘It will be easier to fend him off if I’ve already endorsed Harris.’ When Obama called that evening, the conversation lasted less than a minute. Clyburn said the party should unify behind Harris and that ‘anything else will lead to a real tough convention, which will lead to defeat at the polls.’”

Biden ultimately announced he was dropping out of the presidential race just before 2 p.m. EDT on July 21, and publicly backed Harris roughly a half-hour later. 

“My very first decision as the party nominee in 2020 was to pick Kamala Harris as my Vice President. And it’s been the best decision I’ve made,” Biden said in a post on the social platform X at the time. 

Obama, who would go on to endorse Harris a couple of days after Biden’s withdrawal, “did not think she should be the candidate,” according to an unnamed confidant cited in “Fight,” liking instead the idea of Michigan Gov. Gretchen Whitmer (D) at the top of a ticket alongside Maryland Gov. Wes Moore (D). 

The forthcoming book “Fight” details the contentious dealings within the Democratic Party throughout the 2024 election as Biden, then the oldest sitting president, stared down a tough reelection battle against President Trump, who was seeking an unprecedented return to the Oval Office even as he faced myriad legal battles.

Some Democratic Party officials started planning for Biden’s death or withdrawal as early as 2023, according to Parnes and Allen. And though party and administration officials insisted Biden was capable of manning the Oval Office for another four years, some were well aware of his frailties ahead of his withdrawal, and his team took extensive steps to cover up signs of aging. 

Once Harris was running, she grappled with her sense of loyalty to Biden, and pressure from the president to keep “no daylight” between them contributed to her not distancing herself from him.