I can't believe I have to spell this out, but: You don't get a *boost* in the polls if people think you have a life-threatening illness. Remember the Hillary health rumors? It wasn't Democrats who were spreading those.
And no, "But he's planning to show off his miraculous 'recovery' in two weeks!" is not a good counterargument. PEOPLE ARE ALREADY VOTING.
A few people tweeted arguments like this at me last night, so let me point out quickly that public sympathy three years before an election is not the same as getting voter support one month before an election. https://twitter.com/sammcmorris/status/1312000326430531586
Also, BoJo's surge came before, not after, he announced he had the virus. https://twitter.com/HellaDev/status/1311997243453562880
Also, if your analysis is based on how you think his base will respond, you're looking at the wrong voters. https://twitter.com/KevinRomeis/status/1312006474541998082
The Michael Dukakis health rumors would like a word. https://twitter.com/AmberBenson/status/1312005246915416065
"He's distracting you!" takes are usually wrong. Especially this one, since "He might not be able to fulfill his duties" is going to strike many voters as more important than a FLOTUS tape. (Also, getting COVID is a weird way to distract from COVID.) https://twitter.com/MCTW5/status/1311998783928979456
One last point, because I keep seeing this idea floating around: HE THINKS HE WON THE DEBATE. He doesn't want to duck another one. https://twitter.com/hermannkarlovic/status/1311967321175490561