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Vice President Kamala Harris raked in a staggering $310 million in fundraising in July, her campaign announced on Friday morning, in what it touted was "the biggest haul of the 2024 cycle."

The fundraising by the Democratic Party's presumptive presidential nominee was more than double the $138.7 million that Donald Trump's campaign announced on Thursday that the former president brought in last month.

Harris has enjoyed a fundraising surge in the 12 days since President Biden, in a blockbuster announcement, ended his re-election campaign and endorsed his vice president to succeed him at the top of the Democratic Party's ticket.

The embattled president's immediate backing of Harris ignited a slew of endorsements for the vice president by Democratic governors, senators, House members and other party leaders. Within 36 hours, Harris announced that she had locked up her party's nomination by landing the verbal backing of a majority of the nearly 4,000 delegates to this month's Democratic National Convention.

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Over 10,000 at a Kamala Harris rally in Atlanta, Georgia

Vice President Kamala Harris speaks during a campaign rally, Tuesday, July 30, 2024, in Atlanta. (AP Photo/John Bazemore) (AP Photo/John Bazemore)

The Harris campaign, in announcing their July fundraising, highlighted that more than $200 million was brought in during the first week after the vice president replaced Biden. They called it the "single greatest week in fundraising history" and touted that July was the "best grassroots fundraising month in presidential history."

According to the Harris campaign, two-thirds of the monthly haul came from first-time donors. And they also highlighted that they were sitting on a massive $377 million war chest as of the end of July.

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The July fundraising, by what started out as the Biden campaign and quickly transformed into the Harris campaign, is up from the healthy $127 million that the Biden-Harris ticket brought in during the month of June. Nearly $40 million of that haul came at the end of the month, after Biden's disastrous June 27th debate performance against Trump.

In a sign of support for the 81-year-old president, donors initially shelled out big bucks for Biden in the wake of the debate. 

Joe Biden, Donald Trump

President Biden and former President Trump debated on June 27, 2024 in Atlanta, Georgia. (Getty Images)

But Biden's halting and shaky debate delivery also instantly fueled questions about his physical and mental abilities to serve another four years in the White House - and spurred a rising chorus of calls from within his own party for the president to end his bid for a second term in the White House. The brief surge in fundraising didn't last and by early July, began to significantly slow down.

Meanwhile, Trump's July haul was an increase of over $25 million from the $112 million the former president brought in during the month of June.

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The Trump campaign also reported $327 million cash-on-hand as of the end of July and said in a statement that "these numbers reflect continued momentum with donors at every level and provide the resources for the final 96 days until victory November 5th."

Trump, in a social media post a couple of hours later, pointed to his fundraising and said, "Spectacular support from Great American Patriots who are donating to our Campaign for President of the United States."

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Republican presidential candidate former President Donald Trump dances as he wraps up a campaign rally, Saturday, July 27, 2024, in St. Cloud, Minn. (AP Photo/Alex Brandon) (AP Photo/Alex Brandon)

The Harris campaign has been spotlighting their surge in fundraising since the vice president replaced Biden at the top of the ticket.

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Early last week, the Harris campaign touted that they hauled in $81 million in the 24 hours following Biden's announcement that he was suspending his campaign.

The one-day haul easily topped the nearly $53 million Trump brought in two months ago in the first 24 hours after the former president was convicted on 34 felony counts in his criminal trial in New York City.

A split photo of former President Donald Trump looking off to the right (left) and Vice President Kamala Harris looking off to the left (right).

Former President Trump appears at a rally at the Van Andel Arena on July 20, 2024 in Grand Rapids, Michigan (left). Vice President Harris speaks to NCAA Champion Teams on the South Lawn of the White House in Washington, D.C. (right). (Left: Bill Pugliano/Getty Images, Right: Ting Shen/Bloomberg via Getty Images)

The Biden campaign and the Democratic National Committee enjoyed a fundraising lead over Trump and the Republican National Committee earlier this year. But Trump and the RNC topped Biden and the DNC $331 million to $264 million during the April-June second quarter of 2024 fundraising.

Fundraising, along with polling, is a key metric in campaign politics and a measure of a candidate's popularity and their campaign's strength. The money raised can be used - among other things - to hire staff, expand grassroots outreach and get-out-the-vote efforts, pay to produce and run ads on TV, radio, digital and mailers, and for candidate travel.

Get the latest updates from the 2024 campaign trail, exclusive interviews and more at our Fox News Digital election hub.