I don’t mean that conservatism in general is dying. But what I and others mean by “movement conservatism,” a term I think I learned from the historian Rick Perlstein, is something more specific: an interlocking set of institutions and alliances that won elections by stoking cultural and racial anxiety but used these victories mainly to push an elitist economic agenda, meanwhile providing a support network for political and ideological loyalists.

By rejecting Mr. Cantor, the Republican base showed that it has gotten wise to the electoral bait and switch, and, by his fall, Mr. Cantor showed that the support network can no longer guarantee job security. For around three decades, the conservative fix was in; but no more…

So whither movement conservatism? Before the Virginia upset, there was a widespread media narrative to the effect that the Republican establishment was regaining control from the Tea Party, which was really a claim that good old-fashioned movement conservatism was on its way back. In reality, however, establishment figures who won primaries did so only by reinventing themselves as extremists. And Mr. Cantor’s defeat shows that lip service to extremism isn’t enough; the base needs to believe that you really mean it.