One of the more pernicious quirks of English usage to arise in the past few years is the employment — by a remarkably large number of people, it seems to me — of the term "gaslighting" as the default explanation for disagreement. Nobody just disagrees with me anymore, they’re trying to gaslight me.

Let's remember where the phrase comes from: a 1944 film in which a husband attempts to make his wife think that she's crazy. To say that someone is gaslighting you is to say that they know you’re right but are pretending not to. They’re maliciously trying to get you to doubt yourself. They are dishonest, deceitful, manipulative. The charge of gaslighting is an extreme form of Bulverism: Instead of claiming You say that because you’re a man or You say that because you’re an American it’s You say that because you’re a moral monster. 

It’s a useful tactic to deploy if you’d prefer never to think about whether any of your assumptions are correct. Your opponents are not only wrong, they are wicked, and why should you engage with arguments that are obviously made in bad faith and for evil purposes? These convictions keep your echo chamber hermetically sealed.

What I find especially interesting about this usage is that it seems to have been adopted with equal eagerness by extremists on the left and the right. (Unlike the structurally very similar red pill/blue pill meme, which has been totally co-opted by the right.) It's one of the many ways in which the far left and the far right are continually borrowing language, rhetorical strategy, and in some cases even direct political strategy from one another. It would be nice if we could ship them all off to their own island where they could fight it out, or, perhaps, discover that they can't tell one another apart.