Commentary Ever since the publication of “The Authoritarian Personality” in 1950, liberals and leftists have often chosen a particularly cheap course of handling their conservative adversaries. The tactic works like this. When a progressive point or position is forwarded and conservatives dispute it, progressives don’t answer the objection on its own terms, refuting it with more facts or better logic or even anecdote or humor. Instead, they address the conservative opponent himself—his motives, experiences, feelings, and aims. Not all of them, mind you, only the ones that, putatively, have led the conservative to oppose the progressive idea, his anxieties, insecurities, worries, and fervid imaginings. Whatever principles or values or concepts the conservative articulates, however urgent the reasoning, those things are, in fact, said to be a disguise, a cloak, a tool of deeper irrationality. This is the shift. We go from debate to diagnosis. It’s a potent rhetorical weapon. It has …