Brian Blanco/Getty Images

President Trump might never hold another re-election rally in person, at least if his campaign follows the warnings of health experts who say large gatherings of people might not be safe until "the later part of 2021."

His campaign, though, maintains Trump hasn't held his last rally just yet. "This coronavirus will pass and the president is looking forward to getting back out on the campaign trail and holding rallies," his campaign communications director, Tim Murtaugh, told ABC News on Friday.

Health officials are less confident. "Larger gatherings — conferences, concerts, sporting events — when people say they're going to reschedule this conference or graduation event for October 2020, I have no idea how they think that's a plausible possibility," Zeke Emanuel, the vice provost for global initiatives and director of the Healthcare Transformation Institute at the University of Pennsylvania, told New York Times Magazine recently. "I think those things will be the last to return. Realistically we're talking fall 2021 at the earliest."

Trump, aware of the importance of rallies to his re-election campaign, has floated the possibility of holding events "where you'll have seats where every three or four seats you have empty, you'll have some fill in, and then ultimately we'll have it fill in as the virus is gone," according to audio obtained by ABC News. Other campaign strategists are looking increasingly into how Trump might be able to have gatherings in "low risk" states, or entirely virtually.

"There is no doubt that Trump's rallies have been one of the most effective forms of campaigning we've seen in our lifetime," said Republican strategist Jen Kerns. "It would be the Democrats' dream come true if this were to come to an end." Read more at ABC News.