Advisers and major givers said on Sunday that they were being inundated with enthusiasm and word of planned donations to support Harris if she became the official Democratic candidate — even as questions remained about how to best support her. Shortly before 5pm Eastern time on Sunday afternoon, the Biden campaign filed paperwork formally renaming its campaign committee “Harris for President”.

In the immediate aftermath of President Biden’s decision to exit the race, Harris was enjoying some broad, swift consolidation among major givers. Multiple Biden donors and their advisers said that they were hearing from previously despondent donors who were ready to give to support a Harris-led ticket. One Silicon Valley bundler raised over $1 million in a 30-minute period, the person shared.

Alexandra Acker-Lyons, a Democratic donor-adviser who has spent the last few days behind the scenes trying to raise pledges for Harris, said that she had “gotten a barrage of emails, texts and calls” with promises to give. People who hadn’t given at all asking where to give,” she said.

Gretchen Sisson, a top Democratic bundler in California and a supporter of Harris, said the announcement was met with enthusiasm in her circles, and that she was collecting pledges that she could collect on later in the week. “My phone is exploding,” she said. “Lots of folks are asking where to contribute, what they can do to support the campaign, and wanting to write more. People who were committed but worried are now excited and energised.”

The endorsements came in hard and fast on Sunday afternoon from the Democratic Party’s billionaire class, the type of people who can write a 7- or 8-figure cheque to an outside pro-Harris group.

Reid Hoffman, the Democratic mega-donor who was among Biden’s strongest supporters, endorsed Harris for the presidency. Another major backer of Biden, Alex Soros, the heir to the Democratic philanthropist family, said he was backing her as well.

New York Times News Service