US Vice President Kamala Harris clinches majority of delegates ahead of Democratic National Convention next month.

United States Vice President Kamala Harris has pledged to take the fight to Donald Trump as the Democratic Party’s presidential nominee, invoking her former career as a prosecutor who took on “predators” and “fraudsters”.

Rallying supporters in her first campaign appearance since her boss Joe Biden’s exit from the presidential race, Harris said on Monday that she had taken on “perpetrators of all kinds” while serving as a prosecutor and attorney general in her home state of California.

“Predators who abused women, fraudsters who ripped off consumers, cheaters who broke the rules for their own gain. So, hear me when I say I know Donald Trump’s type,” Harris told campaign staff in Wilmington, Delaware.

Harris, 59, previously leaned on her record as a prosecutor during her unsuccessful run during the 2020 Democratic primaries, which featured the slogan, “Kamala Harris, for the people.”

Since then, Republican presidential nominee Trump has been convicted of falsifying business records, found civilly liable for sexually abusing a magazine columnist and indicted in two criminal cases related to efforts to overturn the result of the 2020 election.

Harris’s combative campaign speech came as she cemented her status as the de facto Democratic nominee amid a wave of endorsements from top party figures, including former House of Representatives Speaker Nancy Pelosi, Pennsylvania Governor Josh Shapiro and Michigan Governor Gretchen Whitmer.

Donors have also rallied behind Harris, contributing a record $81m in the 24 hours since she announced her bid for the White House, according to her campaign.

While Democrats will not officially choose their nominee until their national convention next month, Harris has already won the endorsements of far more than the necessary number of delegates needed to win the nomination.

Harris had more than 2,500 delegates, well beyond the 1,976 needed to clinch the nomination on the first ballot, as of Monday night, according to a tally by the Associated Press.

In his first public remarks since stepping aside amid concerns about his age and fitness, Biden, 81, called in to Harris’s event to pledge his support for her campaign.

“The name has changed at the top of the ticket but the mission hasn’t changed at all,” he said, adding that dropping out was the “right thing to do”.

While Democrats hope that Harris will energise demoralised voters after weeks of turmoil over Biden’s faltering candidacy, she faces lingering questions about her electability.

The former senator has trailed Trump in most opinion polls – only faring as well or slightly better than Biden – and struggled to gain momentum in her 2020 presidential run, dropping out of the race after polling behind Biden, Senator Bernie Sanders and Senator Elizabeth Warren in her home state.

In her speech, Harris, who would be the first Black woman president if elected in November, cast the election as a choice between the future and the past.

“Our campaign has always been about two different versions of what we see as the future of the country – two different visions of our country: One focused on the future, the other focused on the past,” Harris said.

“Donald Trump wants to take our country backward to a time before many of our fellow Americans had full freedoms and rights.”

Harris said Trump would put social security on the “chopping block” and treat healthcare as “a privilege for the wealthy”.

“America has tried these economic policies before. They do not lead to property, they lead to inequity and economic injustice, and we are not going back,” she said.

“We are not going back. They are not taking us back.”