Yet at the White House he shunned one of the simplest and most effective ways of preventing transmission — wearing a mask. “Take that f—ing thing off,” he demanded more than once to aides who showed up wearing masks in the early days of the virus, when he’d been told they weren’t a fail-safe. “It doesn’t look good.”

Mirroring his administration’s fitful efforts to combat the virus outside its walls, testing within the White House was viewed by some who worked there as ineffective. Some aides believed the White House didn’t do enough to take basic safety precautions and wondered whether the public would be kept in the dark about any outbreak inside its walls.

Walking into one coronavirus task force meeting in the Situation Room with Vice President Mike Pence, Treasury Secretary Steven Mnuchin expressed alarm at the crowded space, according to several people present for the episode in the spring.

“We’re violating all the protocols!” Mnuchin said, dragging his chair away from the table. Pence began to orchestrate a rearrangement of the seating, with some attendees leaving the room to sit in an overflow area or join by telephone.