The Democratic fundraising infrastructure has experienced a remarkable revival following President Joe Biden’s historic decision to withdraw from the presidential race and endorse Vice President Kamala Harris as his successor. This pivotal endorsement catalyzed a significant resurgence in donor engagement, reflecting a dramatic shift in the financial dynamics of the campaign.

ActBlue, the leading online donation processing platform for Democratic causes, recorded an extraordinary influx of contributions in the wake of Biden's endorsement. By 9 p.m. Eastern on the day of the announcement, ActBlue had already amassed $46.7 million in small-dollar donations. This figure marked ActBlue’s largest fundraising day of 2024, with several hours remaining for further contributions. The surge in grassroots support highlighted the renewed vigor and financial backing now directed toward Harris's campaign.

The following Monday morning, Harris campaign spokesperson Brian Fallon disclosed that, in addition to the small-dollar donations, the Vice President had raised $49.6 million in grassroots contributions since Biden’s endorsement. This substantial influx of funds underscored the significant impact of Biden’s decision on the financial trajectory of Harris’s campaign.

Beyond the small-dollar donations, a notable uptick in contributions from large-dollar donors was also anticipated. Chris Korge, finance chair for the Biden Victory Fund, described the situation as an impending deluge of support. Korge explained to NBC News that many potential donors had previously refrained from contributing due to the paralyzing effect of the campaign’s uncertainty. He reported receiving numerous calls from major donors who were profoundly moved by Biden’s endorsement, with some expressing emotional responses. “People are emotional because they knew how hard it was to make this decision after doing an incredible job,” Korge remarked. “Major donors are incredibly receptive to his endorsement and are genuinely excited. I think this is going to create a tidal wave of donations.”

ActBlue further amplified the scale of the fundraising surge through its X account on Sunday, revealing that small-dollar donors had contributed over $27.5 million within the first five hours of Harris’s campaign launch. This post emphasized the enthusiasm and eagerness of grassroots supporters to back Harris as the Democratic nominee. Later that day, ActBlue updated its total to $46.7 million, underscoring one of the largest single-day fundraising totals in the platform’s history. The final daily total had not yet been confirmed, but the day's results were already among the most significant ever for ActBlue, which had previously reported $460 million in donations during the first quarter of the year, averaging just over $5 million daily.

This resurgence in Democratic fundraising follows a period of severe financial challenges for Biden’s re-election campaign. Since a particularly disastrous debate performance on June 27, major donors had largely withdrawn their support, questioning Biden’s viability as a candidate. The decline in grassroots funding further exacerbated the campaign’s financial difficulties, leaving it in a precarious position just as it needed to ramp up efforts to compete against former President Donald Trump. During this turbulent period, Trump's campaign had experienced a boost in fundraising, particularly in the wake of his criminal conviction in New York in May. By the end of June, filings showed that Trump's campaign and the Republican National Committee had accumulated more funds than Biden and the Democratic National Committee combined.

Joe Cotchett, a prominent Democratic bundler from the San Francisco Bay Area, observed that the mood among donors had shifted dramatically following Biden’s announcement. “Donors are now ready to dig into their pockets,” he noted. John Morgan, a Florida trial attorney and significant Biden donor, anticipated a near-term increase in small-dollar contributions. However, he also revealed that he had stepped down from the campaign’s national finance committee following Biden’s decision, citing a diminished enthusiasm for soliciting donations under the previous conditions.

Democratic donor Gideon Stein, president of the Moriah Fund, had previously paused contributions due to concerns about Biden’s electability. On Sunday, Stein confirmed his intention to resume funding efforts with a focus on Harris. Before his pause, Stein had earmarked $3.5 million for nonprofit and political organizations associated with the presidential race.

Justin Day, a prominent Florida Democratic fundraiser with experience as a finance chair for Hillary Clinton and Barack Obama, predicted that the shift at the top of the ticket would motivate previously disengaged Democratic donors to contribute. “I have already heard from a number of donors who have not participated this cycle who have reached out to tell me they are all in, no matter who the nominee ultimately is,” Day said. “Focus has shifted back to beating Trump.”

In response to these developments, former President Trump expressed his dissatisfaction with the shifting dynamics on his social media platform, Truth Social. He criticized the expenditure on attacks against Biden, who would no longer be a contender in the November election, and questioned whether the Republican Party should be reimbursed for what he perceived as a misallocation of resources. "So, we are forced to spend time and money on fighting Crooked Joe Biden, he polls badly after having a terrible debate, and quits the race. Now we have to start all over again," Trump wrote. "Shouldn’t the Republican Party be reimbursed for fraud in that everybody around Joe, including his doctors and the Fake News Media, knew he was not capable of running for, or being, President? Just askin’?”

The swift resurgence of financial support for Harris underscores the profound impact of Biden’s endorsement and highlights the evolving landscape of political fundraising in the wake of significant campaign developments.