Any sane person who reads this tweet has a strong impulse to impute a satiric or otherwise comedic intent on the part of its author. That would be a mistake. This is the president of the United States, and he’s not joking around or kidding on the square or being taken seriously not literally or whatever other nonsense people tell themselves to hide from the truth.
This is 25th amendment territory. I do think we’re in a kind of gray zone here in terms of timing: if the election were next month, then obviously nothing would happen because hey the election’s next month. If this were October 2018, I think it’s actually likely that a lot of important people would all decide that we can’t do this for two more years. But we’re right in the middle so . . .