What happens is is that these congressman build a circle of aids who handle all the real work while they campaign. Those aids develop working relationships with other aids. The more senior, the more influence they have. It quickly gets to the point when the politician themselves are just a figurehead and the aids don't want to start over with a new one, so they just wheel their host around.
Trump is well into the category where he's just being lead around by his handlers.
He can do 20 more years. Weekend at Bernies is also possible. No crazy scheme is off the table in today's America. Trump may also just be laying out the red carpet for some even crazier lunatic. Maybe hereditary dictatorship? Elon? Nothing is off the table at this point. Fuck me and the bleak possible future.
Once they force three terms onto Trump they can use whatever flimsy justification they have found to allow three terms for Vance or whoever they get to replace trump.