If Trump does primary a significant number of Republicans and manages to depose even a few, that will, I suspect, push a lot of moderate Republicans to vote Democrat (possibly for the first time). This will make the mid-terms... interesting.

In addition, if enough credible talk about violence is picked up, there's some chance that some pro-prison-industrial complex folks will get to see the inside of the prisons that they're so certain are the right way to deal with drugs and thugs. This, for them, will serve to be... instructive.