There's an idea called "stochastic terrorism". Stochastic, I gather, is a term relating to probability. And the idea is, basically, that if you keep inciting anger at a specific target, chances are that sooner or later something is going to happen.
If your conspiritard radio show has a million listeners and you keep saying that Comet Pizza has a basement with a dungeon full of captive children, chances are that at least one of your million listeners is nuts enough to decide to take his gun and go "free the children".
If the far right internet sphere keeps saying that Soros, Obama, and the Clintons have an agenda to destroy America, chances are that somebody in that sphere is going to decide to "save America".
Jones or Trump or Hannity or whoever may not have ever told anybody to mail bombs to prominent Democrats, but listening to these people talk you can certainly imagine why somebody got the idea that they have to do something to "save America" from those people. It only takes one in a million.
-k