I would say Trump supporters.
9/11 conspiracy believers have done no harm. At the very least they've stimulated public consciousness and discussion of 9/11.
Trump supporters, OTOH, have done some real damage to the US. Their impulse was brutal and atavistic. They looked America straight in the eyes while they stuck the knife in. They were so angry, so outraged, so revolutionary-minded that they were willing to hurt themselves to hurt everyone else. In fact TrumpCare (tm) will hurt them even more!
There's an old joke about a woman whose husband finds out she's been cheating. She says it's because he's a moron. He gets all emotional, he pulls a gun out of a drawer and points it at his head. The wife says 'Oh, so you're gonna kill yourself now?' He says 'Don't laugh. You're next.' THAT'S the Trump voter.