Conservatives preserve a better memory of how extreme these figures were. That’s why names like Bill Ayers, who founded the terrorist group Weather Underground, and Herbert Marcuse, who taught Davis philosophy, and Saul Alinsky, who tried (unsuccessfully) to reconcile the old and new lefts, acquired prominent positions in the demonology of the right. According to writers like Newt Gingrich, Norman Podhoretz, and Mark Levin — as well as less famous talk shows, bloggers, and social media influencers — the modern Democratic Party is little more than a vehicle for the New Left aspiration to fundamentally transform America.

Especially in more lurid versions, such assertions are easy to dismiss as conspiracy theories or guilt by association. What critics tend to miss, though, is that they’re inspired by envy as well as revulsion. Conservative writers and activists are almost unanimous in rejecting the New Left’s goals. But many see them as authors of a how-to guide for imposing an unpopular and disruptive agenda on an initially recalcitrant majority. The flamboyance, militance, and violence of the 1960s left might not have worked right away, after all. In the long run, though, ideas about social justice, national guilt, and sexual freedom that seemed bizarre and dangerous at the time are now thoroughly mainstream features of American life.