For decades, the politicians on both sides have set this up. Because what ever political idea is being pushed, whoever was against it was something less than a human and called such. It has degraded to the point now if you are not for whatever it is, you are no longer the opposition, you are the enemy. It's bad enough that the unpopular things that have been done in congress, have resulted in the republican party telling their congress critters not to hold town meetings because the animosity from their actions are coming home to roost with the populace. Sooner or later they must face the voters for a re-election.
The word "compromise" has totally been forgotten. In that viewpoint, nothing gets done. It's been 25 years since last a budget has been passed, as just such an example. Now, people angry at the lack of progress, are taking matters into their own hands to try and force it done. For the moment, it's just the nutcases doing this. How long before it seeps down the regular populace? Already the few congress critters that have held town halls have gotten their ears full from highly dissatisfied voters they represent; doesn't matter the party holding it.
Trump has been the final straw to start really bringing these events to a head. Displaying the "you are the enemy" for his opposition, for all to see. Even before the shooter was caught, with no information, he was right in there claiming the Dems were the cause and who had to be dealt with. Stacking the voter rolls through gerrymandering won't make this go away. While they may or may not stay in power, the anger under the surface by the voters who the congress critters are supposed to represent, will continue to simmer until things start being taken care of again. It's not going to get better until congress finally figures out it's about the people, not the party.
The Republicans have dug their own hole following Trump. As enablers, if left alone, they aren't going to fair so well. It's midseason elections and typically, what ever party is in power, loses. Trump is desperate to change this so he can have his way of doing things continue.