Maybe it’s soft handed liberalism? Too close an examination of the body-politic would make people actually look at themselves and the circles they run with? It might cost you some friends at social events?
It’s not just Trump, though he is the iconoclast. Just like LBJ and Reagan before, a popular(ist) leader will transform the party and nation by shifting the Overton Window of what is ‘normal and accepted’ in the political arena.