She argued in part that “the kind of racism that’s most common in movement conservatism is ‘instrumentalized’ racism, the deliberate use of racism and racist tropes for the sole purpose of winning votes and elections.” Those who exploit it do so “not necessarily because they themselves are ‘racist’ on an individual level,” Coaston wrote, “but because they believe that voters will respond—and perhaps only respond—to racism.”

I concur that Trump, as surely as Lee Atwater, marshals racist tropes. But I doubt the last claim: “Instrumental racists” believe that voters will perhaps respond only to racism. And I doubt that voters, in fact, respond only to racism. Something distinct and deeper is at work. This deeper force explains nearly all of Trump’s most odious and irresponsible comments, not just the racist ones. It helps explain why so many conservatives and Republicans were caught off guard by Trump’s rise and the resonance of his bigotry. And it helps clarify what the left sees and doesn’t see about racism. Once leftists understand it, they will find it easier to defeat the identitarian right.

No one better anticipated today’s societal divisions than the political psychologist Karen Stenner, author of the 2005 book The Authoritarian Dynamic. The book built on research literature that distinguishes between “authoritarians,” who prize what Stenner calls “oneness and sameness” so much so that they are prone to support coercion to effect it, and “libertarians,” who not only defend but affirmatively prize diversity and difference. (Those labels are not to be conflated with the popular definitions of the terms.)

Stenner began her research with a questionnaire that probed the attitudes of her subjects toward child-rearing. Their answers indicated the extent to which they think that it’s more important for kids to obey their parents, have good manners, be neat and clean, and follow the rules—or alternatively, that it’s more important that they are responsible for their own actions, and creative, curious, independent thinkers who follow their own conscience and show good judgment. Designed to provide an unobtrusive, bare-bones measure of each subject’s fundamental stances toward conformity and difference, the child-rearing questionnaires were scored and the subjects arrayed from most libertarian to most authoritarian. Stenner was most interested in the people who scored at the extreme poles.

She thought that both the most extreme authoritarians and the most extreme libertarians have powerful, largely innate and highly durable psychological predispositions that affect how they react to all that is unfamiliar and different. Trying a new cuisine, attending a different faith’s religious service, or carpooling for a week with someone of a different race is energizing, exciting, and engaging for one type of person but leaves the opposite type frightened, even “unhinged.” And she wondered how those predispositions would influence how intolerant (if at all) a person was likely to be when circumstances confronted them with racial or political or moral differences.