“We’re living in a terrible time in America where truth has died,” Mr. Savage, who was one of the first conservative media stars to urge Mr. Trump to run for president, told his audience. “This is crazy,” he added, pointing to the way the president’s defenders always accuse the left of spreading “fake news.”

“How can we not let our side be called on the carpet when they lie to the people?”

That was Feb. 24.

At the time, coronavirus outbreaks were largely limited to a handful of countries like China, South Korea and Italy. Only a few dozen cases had been reported in the United States. The same day, Rush Limbaugh likened the coronavirus to the common cold on his radio program. But it spread aggressively in America just as Mr. Savage had warned it would — a prediction that earned him the ire of people who called him a hysteric and a sellout.

His contempt for hosts like Mr. Limbaugh and Sean Hannity, whose top-rated radio shows draw more than 30 million listeners each week, is especially searing. He mocks them as “Dr. Hannity” and “Rush Limbaugh, M.D., Ph.D.,” belittles their lack of education compared with his, and berates people who took their claims seriously.