The key to keeping Trump on mission, to the extent that we can, is the same thing they keep using co-opt him: he just wants to be liked. Every other politician in their last term, who doesn't have to worry about being reelected, will only care about how big the payout is after they retire from office: how many corporate boards they and their family are asked to sit on. They don't care what the plebs think of them. But Trump can't stand the thought of poisoning his legacy in the eyes of his own base. He wants to be remembered as a hero.