U.S. Vice President Kamala Harris addresses a crowd of supporters during her first campaign event as a candidate for president at West Allis High School in West Allis, Wisconsin, U.S., July 23, 2024. / REUTERS/Kevin Mohatt

INDIANAPOLIS (Reuters) - U.S. Vice President Kamala Harris called on a rally of more than 6,000 Black women on July 24 to help her revitalize the Democratic presidential campaign, ahead of her Republican rival Donald Trump's return to the campaign trail.

Harris has emerged as the Democratic presidential candidate in the Nov. 5 election after President Joe Biden, 81, ended his re-election bid on July 21 in the face of intense opposition from fellow Democrats who questioned his ability to win or to serve for another four years were he to do so.

The 59-year-old vice president, the first Black woman and Asian American to serve as vice president—who would also be a historic first as president if she prevails over former President Trump, 78—has shaken up a staid race and sparked new energy among Democrats.

That surge will not go unanswered on July 24 , when Trump holds his first rally since Biden ended his campaign in the battleground state of North Carolina. The Trump campaign has insisted it is prepared for Harris' candidacy, arguing she serves as a proxy for Biden on the economic and immigration policies that contributed to his sinking popularity with voters.

Harris spoke at an event in Indianapolis hosted by the Zeta Phi Beta Sorority, which was founded at Howard University, the historically Black college she attended. She hopes to tap sororities' multi-generational network of Black women, who played an important role in Biden's 2020 victory, to deliver strong voter turnout for Democrats again in November.

"I thank you. And now, in this moment, our nation needs your leadership once again," Harris said.

Harris and Trump are closely competitive, public opinion polls showed this week.

A Reuters/Ipsos poll completed on July 23 showed Harris with a marginal two-percentage-point lead over Trump, 44 percent to 42 percent. A CNN poll conducted by SSRS showed Trump leading Harris, 49 percent to 46 percent. Both findings were within the polls' margins of error.

BIDEN TO SPEAK

Biden, who came back to Washington after isolating at his home in Delaware with COVID, will address the nation from the Oval Office on July 24 night to explain his decision to drop out after a disastrous June debate with Trump raised questions about his ability to win the election, or to serve another four years if he succeeded.

On July 23, Trump took the unusual step of speaking to reporters on a conference call to underscore his campaign's line of attack on the border, saying Harris was partially responsible for a record flow of migrants.

Biden put Harris in charge of working with countries in Central America to help stem the tide of migration, but she was not made responsible for border security.

“She's a radical left person, and this country doesn't want a radical left person to destroy it,” Trump said on the call. “She wants open borders. She wants things that nobody wants.” Harris has not called for the removal of border controls.

Trump, coming off a triumphant week in which his party unified around his presidential bid after a failed assassination attempt two weekends ago, has had to watch as Biden's sudden departure from the race dramatically shifted the narrative and sparked a surge of attention toward Harris at his expense.

Harris campaign chair Jen O'Malley Dillon said in a memo made public on July 24 that Democrats would aim to compete in the swing states of Michigan, Wisconsin, Pennsylvania, North Carolina, Georgia, Arizona and Nevada, opening up a map that in the final weeks of Biden's campaign had appeared to be more focused on the Midwest.

"This race is more fluid now – the vice president is well-known but less well-known than both Trump and President Biden, particularly among Dem-leaning constituencies," O'Malley Dillon wrote.

Democrats will formally nominate their new ticket at next month’s convention in Chicago after an Aug. 7 virtual vote. Roy Cooper, North Carolina's Democratic governor, is considered to be on the short list to serve as Harris’ running mate.

Harris and her campaign have worked at breakneck pace to consolidate support among Democrats in Congress and delegates across the country. Candidates who could have been potential rivals for the nomination have fallen in line and endorsed her.

The Harris campaign on July 24 said it has raised $126 million since July 22, with 64 percent  of donors making their first contribution of the 2024 campaign.