And, from The New York Times:
...When Mr. Cain was hospitalized, Mr. Calabrese said that in addition to attending Mr. Trump’s indoor rally in Tulsa, Okla., on June 20, he had done “a lot of traveling” recently.
“I don’t think there’s any way to trace this to the one specific contact that caused him to be infected,” he said at the time. “We’ll never know.”
In a video posted to his website after the president’s rally, Mr. Cain said he had worn a mask while in groups of people. But he also posted photographs of himself on social media that showed him without a mask and surrounded by people in the arena...