Whitmer I reckon, Progressive governor of a swing state, and who knows first hand that the ultra right are fucking dangerous loons that need the hand of God brought down on them.
Manchin (though I doubt the democrats would allow it)
Honestly, if he announces his candidacy for 2024, I suspect a chunk of the "You're a Trump supporter if you are even slightly dissatisfied with Biden" crowd will happily jump ship.
Trump won't win the nomination in 2028, so if he's still alive and still semi-intelligable, he'll launch a third party campaign that splits the conservative vote and gives the Dems 4 more years. You saw it here first.