Every one of them have joined a stupid cult like group for that sense of belonging and affirming their place in the group/world.
He plays on that. It works. They’ll follow one idiot, so they’ll follow another.
And their value system - as shown for republicans - is very upside-down: Trump has validity because he’s in the group, and the group is great because he’s in it and so he’s allowed in it. It’s seemingly not the other way around where he can’t join the group as a cad and a cheat. It’s amazingly circular too.
So yeah: joiners are his thing, and he gives them all the (little-s) social security they crave at the mere cost of them committing treason for him and going to jail.