Nothing quite so drastic has occurred amid the anxiety of the current moment, one that reflects, perhaps, a collision of forces both economic and existential. First, we have endured the decades-long sputtering of the industrial engine that once powered America’s towns and cities, the shuttering of factories and downtown storefronts. This has created the sense among some voters — not always illusory, by any means — that their jobs and neighborhoods are endangered by interlopers, a fear that has empowered a long line of populist politicians and commentators.

And then came the cataclysm of 2001, when a new era’s foreign enemies made themselves known on American soil, leaving in their wake a lingering sense of vulnerability, reminiscent of the cold war.

These trends have opened the door, once again, to nativist appeals — some more subtle than others. And because of the political realignment that began in 1980 (when the term “Reagan Democrats” — meaning ethnic whites — entered the lexicon) and reached its apex in 1994, when the South tipped into the Republican column, the voters who are most susceptible to such appeals reside, at this juncture in our politics, primarily in the Republican base.