4chan

I mean that is part of it. The NRA has people living in a collective delusion. This delusion appeals particularly to people who are dejected or vulnerable because it gives them something like an ego safety net. So when the inevitable happens, and some of these people "snap," they have nearly ubiquitous tools available to make it everyone else's problem.

Gun availability is a big part of the problem, but the even bigger issue is the culture of fear the NRA and Republican politicians have pushed to sell more guns, and how that intersects with other social ills in the US.