Run for Something has canceled events through mid-June, which Litman estimated will cost the group $450,000, approximately 25 percent of its budget for the year.

Both Trump and Biden, who is just beginning to gear up for a general election as the coronavirus rocks the United States, are trying to keep growing their campaigns. And the committees and campaigns associated with House and Senate candidates have canceled almost all upcoming events, they told POLITICO.

“Safety is more important than fundraisers or negative ads,” Jesse Hunt, a spokesman for the National Republican Senatorial Committee, said in a statement. “In-person fundraisers have been canceled and that will affect our bottom line. And we couldn't care less.”

“This decision will cost us money,” Scott Fairchild, executive director of the Democratic Senatorial Campaign Committee, wrote in an email to online donors explaining the committee was canceling all events. “A large chunk of our fundraising is going to dry up. And to compensate for this shortfall, our Democratic Senate campaigns will need the support of this online community more than ever.”

Trump’s campaign has canceled a slew of events, including a pair of highly anticipated fundraisers featuring Melania Trump — her first for the reelection campaign — this week in Beverly Hills and next week at Trump’s Mar-a-Lago resort. Trump also last week canceled a trip to Las Vegas for a fundraiser hosted by casino mogul and Republican megadonor Sheldon Adelson.

“Trump’s fundraising juggernaut is certainly going to slow a bit as the country focuses on survival,” said Republican donor Dan Eberhart. “It may not be evident today, but campaign fundraising is certain to take a hit like every other sector of the economy. There is too much uncertainty for large and small donors alike.”

Both Trump and Biden will keep raising money online and via “virtual fundraisers,” held most often through video conferences with donors. Biden has one such virtual event scheduled for Friday. (The transition hasn’t always been easy: The Biden campaign postponed one such event scheduled for this week in New York City amid technical difficulties, CNBC reported.)

Earlier this week, the Biden campaign distributed a fresh list of incentives to its top fundraisers to try to keep money flowing in: perks for bundlers who raise $25,000 to $500,000 for the campaign. A fundraiser who raises $25,000 for Biden, known as an “Advocate,” gets “direct contact with Regional Finance Director” and “Inclusion in national leadership councils.” People who raise more money for the campaign — including the $250,000 “Scranton Circle” and the $500,000 “Philly Founder” — receive more perks, including “bi-weekly update calls with campaign leadership” and invitations to quarterly and annual finance committee events.

“It may become more 'social distancing' or more draconian down the road, then eventually people will realize we need to move forward with the campaigns as well. Some of that means resources,” said John Atkinson, a Chicago-based bundler for Biden.