For the last 10 years, we’ve been hearing that President Donald Trump will preside over the end of democracy in America. In liberal circles, that assertion is often accepted as fact. For many, the proof is in the evidence from other countries’ democratic declines. A whole genre of American political writing is issuing this warning. Perhaps the best known entrant is How Democracies Die, by the Harvard political scientists Steven Levitsky and Daniel Ziblatt. The authors mention a few democracies that fought off authoritarianism but overwhelmingly recount just what the title says: how democracies die. There are many other examples...