What is populism?

Michael Gerson is the latest opinionator to ask whether ours is a populist moment. He's smart enough to realize that the question begs another, so he attempts a definition of populism. His mistake is to attempt to idealize populism as he defines it, in order to exclude both Donald Trump, on the right, and Bernie Sanders, on the left. Trump is out because he espouses a "conspiratorial nativism" more akin to the Know-Nothing party. Sanders is out because, insofar as he is a social democrat, if not a democratic socialist, he is a technocrat and has a "faith in experts" that Gerson recognizes as alien to populism. For Gerson, the ideal populist would be someone like Pope Francis, who like American history's definitive populist (according to Gerson), William Jennings Bryan, combines compassion for the poor with religious traditionalism. Like most who attempt to define populism, Gerson finds "anti-elitism" at its heart. Unlike some, he tries to exclude xenophobia from populism, at least in its ideal form. Unfortunately, populism is rarely anti-elite without also being anti-other. It seems to come with the conviction that a certain group of us are the authentic People for whom populism is named, while others, both above and below, are not. Gerson notes that the original capital-P Populists of the late 19th century, who briefly turned the People's Party into a major force in politics, had a democratizing agenda, being early advocates of the direct election of U.S. senators, stock market regulation, etc. Some of the early Populists hoped to topple the elites by crossing racial barriers, but their efforts failed and some Populist leaders proved rabid racists. If "populism" is to have a specific meaning, if it isn't just a synonym for "democratic" or "progressive," its exclusionary impulse has to be recognized. Something reactionary about it should be acknowledged as well, because it effectively distinguishes a populist attitude from a progressive one. While some observers have dubbed Sanders or his supporters populists, Gerson senses that it isn't so, and the Vermont Senator's technocratic leanings, such as they are, are only part of the difference. To the extent that Sanders is a socialist or a progressive, he presumably recognizes the need for comprehensive social (if not cultural) change. Populists, too, can call for change if change is necessary to bring the elites or the outsiders under control. Where they draw the line, I've long suspected, is when anyone says that they have to change. That's probably why populism tends to be a dead-end as a political movement, and why it remains a constant if nebulous presence in modern politics.