Dangerous social movements like ISIS and the Far Right have things in common but of course not everything. The Far Right isn't anywhere near as dangerous as ISIS, not by a long shot despite frantically loose parallels drawn lately. Still, they have things in common, chiefly that they're like self-winding watches.
No matter how you shake self-winding watches they wind themselves up. No matter how you shake dangerous social movements they wind themselves up, too.
Support, opposition, confirming or disconfirming news, their claims proving true or false - it doesn't matter. Whatever happens is proof that they're on the right track, their mission holy, true and righteous. Everything fuels them.
There are self-winding people, too. Trump is one. Rising poll numbers fuel him, but so does rising opposition. If you disagree with him, it means you're a loser, which vindicates him as a winner by default. With the right spin, it's easy to turn criticism into affirmation. Demonize your critics and their opposition proves that you're right.
Self-winding watches never over-wind, but self-winding people and movements do. That's a huge problem. Since they're not self-limiting, they have to be limited from the outside, but since any attempt to limit them confirms them, it's hard to know what to do.