In the months ahead, Trump will bring his embrace of alternative facts on the nation’s behalf into talks with China, North Korea or any number of powers with interests counter to ours and that constitute an existential threat. At home, Trump now becomes the embodiment of the populist notion (with roots planted at least as deeply in the Left as the Right) that verifiable truth is merely a concept invented by fusty intellectuals, and that popular leaders can provide some equally valid substitute. We’ve seen people like that before, and we have a name for them: demagogues.