Kamala Harris / Erin Schaff/Pool via REUTERS

WILMINGTON, Delaware (Reuters)-U.S. Vice President Kamala Harris, building Democratic backing for her sudden presidential run, rallied supporters on 22 July with a debut campaign speech vowing to go after Republican nominee Donald Trump like the courtroom prosecutor she once was.

"I took on perpetrators of all kinds. Predators who abused women, fraudsters who ripped off consumers, cheaters who broke the rules for their own gain," Harris told campaign workers 28 hours after President Joe Biden, 81, abandoned the 2024 White House race and endorsed her.

"So hear me when I say I know Donald Trump's type. In this campaign, I will proudly, I will proudly put my record against his," said Harris, who was attorney general of California and a U.S. senator before serving as Biden's vice president.

The Trump campaign responded to Harris' comments. "Kamala Harris is just as incompetent as Joe Biden and even more liberal," said Karoline Leavitt, the campaign's national press secretary. "Not only does Kamala need to defend her support of Joe Biden’s failed agenda over the past four years, she also needs to answer for her own terrible weak-on-crime record in California."

Trump is due to be sentenced in September after having been found guilty of falsifying business records to hide hush money payments to a porn star. He also faces criminal charges related to his efforts to overturn Biden's 2020 victory. He falsely claims he lost in 2020 because of election fraud.

Biden, who pulled out of the race on July 21 amid questions about his age and health, called into Harris' campaign event. Recovering from COVID-19 at his home in Delaware, he sounded hoarse but appreciative of his vice president.

Biden said he thought he had made the right decision by dropping out. The oldest person ever to occupy the Oval Office, Biden said on July 21, he would remain in the presidency until his term ends on Jan. 20, 2025.

Harris, 59, outlined a series of policies she promised to pursue including signing laws to protect abortion rights and ban assault rifles, and said she would make rebuilding the middle class the focus of her presidency.

Within minutes of receiving Biden's backing on July 22, Harris began consolidating Democratic support for her presidential bid, securing commitments from hundreds of convention delegates, announcing a massive fundraising haul, and earning endorsements from top party figures.

These included former Speaker Nancy Pelosi, who has remained influential since stepping down as the party's House of Representatives leader in 2022. The AFL-CIO labor union federation, which represents 12.5 million workers, said on July 22 it had also endorsed Harris for president.

The Harris campaign aims to secure commitments from a majority of the nearly 4,000 Democratic delegates to next month's Democratic Party convention by Wednesday evening, sources told Reuters, effectively wrapping up the nomination.

Campaign officials and allies have made hundreds of calls urging delegates to nominate Harris for president in the Nov. 5 election.

Harris' campaign said it raised $81 million in the 24 hours following Biden's exit, the most for a single day in the 2024 campaign for either party.

Virtually all of the prominent Democrats who had been seen as potential challengers to Harris have declared support for her, including Governors Gretchen Whitmer of Michigan, Gavin Newsom of California, and Andy Beshear of Kentucky. Whitmer, in a post on X, on Monday said she would serve as co-chair of Harris' campaign.

Biden's departure was the latest shock to a White House race that included his disastrous June 27 debate performance against former President Trump and the July 13 near-assassination of Trump by a gunman during a campaign stop.

Harris lauded Biden for his service to the country. At a White House event to honor college athletes earlier on July 22, she said: "Joe Biden's legacy over the last three years is unmatched in modern history."

Harris will travel on July 23 to Milwaukee, the largest city in the battleground state of Wisconsin, which last week hosted a Republican National Convention that offered a stark display of Trump's dominance over his party.

NEW GENERATION

Harris, who is Black and Asian American, would fashion an entirely new dynamic with Trump, 78, offering a vivid generational and cultural contrast.

The Trump campaign has been preparing for her possible rise for weeks, sources told Reuters. It sent out a detailed critique of her record on immigration and other issues on Monday, accusing her of being more liberal than Biden.

It alleged that Harris favored abolishing the U.S. Immigration and Customs Enforcement agency and decriminalizing border crossings, backed the so-called Green New Deal, supported the administration's electric vehicle mandates, and encouraged "defund the police" efforts.

Some of those were positions Harris adopted as an unsuccessful presidential candidate in the 2020 election when she was running on a more liberal agenda than Biden but were not ones that the administration assumed, particularly about border security and law enforcement issues.

Eric Holder, who was U.S. attorney general in the administration of President Barack Obama, and his law firm Covington & Burling LLP will conduct the vetting of Harris' potential running mates, according to two sources familiar with the matter.

Trump, whose false claims that his 2020 loss to Biden was the result of fraud inspired the Jan. 6, 2021, assault on the U.S. Capitol, on July 22, questioned Democrats' right to change candidates.

"They stole the race from Biden after he won it in the primaries," Trump said on his Truth Social platform.

At a rally for Trump's running mate, JD Vance, on July 22, Ohio state Senator George Lang called for civil war to save the country if Trump didn't win the November election. Lang later said on X that he regretted the remarks. "We should all be mindful of what is said at political events, myself included," he wrote.

Harris is expected to stick largely to Biden's foreign policy playbook on such issues as China, Iran, and Ukraine, but could strike a tougher tone with Israel over the Gaza war if she wins the November election.

Some Democrats were concerned about the country's long history of racial and gender discrimination. The U.S. has not elected a woman president in its nearly 250-year history.

Most public opinion polls conducted before Biden dropped out did not find that Harris performed better statistically against Trump than Biden had.

Biden has not been seen in public since testing positive for COVID on July 17. He tentatively plans to meet with Israeli Prime Minister Benjamin Netanyahu on Tuesday if he has recovered.