Now we learn he was hiding one more big and dangerous secret. Three days before a presidential debate, Mr. Trump knew but did not say he had tested positive for the coronavirus. Instead, he carried on his campaign and presidential schedule, endangering all those with whom he came in contact.

The disclosure is in a new book by Mr. Trump’s then-chief of staff, Mark Meadows. According to the Guardian newspaper’s summary of the book and multiple former Trump aides, as reported by The Post, Mr. Trump tested positive just before departing for a campaign event in Pennsylvania on Sept. 26, six days before he was hospitalized at Walter Reed National Military Medical Center for covid-19. The White House decided to retest Mr. Trump’s sample using Abbott’s rapid antigen test, Binax, which produced a negative result. A spokesman for Mr. Meadows said the first test was a false positive, but what kind of test was carried out initially has not been disclosed. Mr. Trump called Mr. Meadows’s claim “Fake News.”