I've noticed this effect personally. I've never owned a gun and have no practical use for one, though I've enjoyed target-shooting the handful of times I've tried it. I have no interest in hunting and I live in a nice safe city, not some war zone; having a gun in the house would make me less safe, not more. And yet, whenever the topic of gun control comes up in the news, I find myself musing about the idea of buying one - solely because it might become impossible to do so in the future.
It's easy to understand why people who live in rural areas, or who are emotionally invested in the cowboy-shootout myth or the uprising-against-the-government myth or one of the other American gun myths, might respond to the latest mass-shooting news cycle by going out and buying more guns.