That he never develops serious symptoms. That in a few weeks he comes out bragging that his good genes got him through this, that the virus was nothing, and that he’s vindicated in blowing off any and all concerns about Covid safety.
It’s also plausible this whole thing is made up (even with the complicity of Hope Hicks) and that it’s designed to revive his standing in the polls. Kind of like the stage assassination attempt in the movie, BOB ROBERTS. I tend to think that’s far-fetched, but if he somehow bounces back “like it’s a miracle”, I’ll still have my doubts.
On the other hand, if the virus lays him out–then I’m a believer.