Former House Speaker Nancy Pelosi on Monday endorsed Kamala Harris to replace President Joe Biden at the top of the Democratic ticket, calling her “brilliantly astute” and saying that she is the best person to defeat former President Donald J. Trump in the autumn.

“It is with immense pride and limitless optimism for our country’s future that I endorse Vice-President Kamala Harris for President of the United States,” Pelosi wrote in a statement. “My enthusiastic support for Kamala Harris for President is official, personal and political.”

The statement by Pelosi, who had earlier said she would favour a competitive process rather than a coronation of Harris, was the most significant in a rapidly growing number of high-profile endorsements as Harris moved swiftly to cement her position as the new face of her party. Pelosi urged her colleagues to get behind Harris, saying, “We must unify and charge forward to resoundingly defeat Donald Trump.”

The endorsement came about an hour after Harris made her first public appearance since Biden dropped his re-election bid and endorsed her, praising Biden’s “deep love of our country” as she moved swiftly to clear a path to the Democratic presidential nomination.

Harris spoke at a morning event at the White House after scooping up endorsements from would-be challengers, including governors J.B. Pritzker of Illinois, Gretchen Whitmer of Michigan, Andy Beshear of Kentucky, Wes Moore of Maryland, Tim Walz of Minnesota and Tony Evers of Wisconsin.

Several of them have been talked about as possible running mates.

She faces the daunting challenges of taking over Biden’s campaign structure, fending off opposition to her rise to the top of the ticket and defining herself for the American public before Republicans and their nominee, former President Donald J. Trump, do. A campaign video from her 2020 run was circulating on social media Sunday night, in which she mocked Trump as “a world leader in temper tantrum”.

The Vice-President started off with a tremendous burst of excitement from Democrats willing to put aside past doubts about her. Party members are anxious to end the divisions that have torn the party apart in the weeks since Biden’s halting debate performance persuaded many that he should not remain in the race.

While some other party leaders, like former President Barack Obama, have not endorsed her, suggesting the need for a competition, Harris sought to defuse complaints of a coronation by emphasising in a written statement on Sunday that she intended to “earn and win this nomination”.

With breath-taking speed, Harris took control of Biden’s enormous political operation and contacted Democratic leaders in Congress and state houses to ask for their support. The Biden campaign formally renamed itself “Harris for President”, giving her immediate access to an account that had $96 million in cash at the end of June. On an internal call, the Biden campaign’s leaders told staff members that they would now work for Harris.

“I will do everything in my power to unite the Democratic Party — and unite our nation — to defeat Donald Trump and his extreme Project 2025 agenda,” Harris said in a statement. “We have 107 days until Election Day. Together, we will fight. And together, we will win.”

The rapid turn of events plunged the party and the nation into unfamiliar political territory, giving un-elected Democratic officials the final say over the party’s nominee. Complicated decisions loom. Harris must choose a running mate, take charge of the campaign with little time before early voting begins in some states in September, rebuild support among voters who had fled Biden and prepare to withstand a full-blown Republican assault.

Biden endorsed Harris within minutes on Sunday afternoon. Before she had uttered a word about her intentions, he was swiftly followed by other party leaders, including Bill and Hillary Clinton, key Democratic senators and influential House members. By the evening, Shapiro had publicly backed Harris after a phone call from her. She also picked up endorsements from governor Gavin Newsom of California, Cooper and Kelly.

Not all Democrats were pushing for a coronation. Neither Senator Chuck Schumer, the majority leader, nor Representative Hakeem Jeffries, the minority House leader, backed her.

New York Times News Service