Even as a consensus definition of populism remains elusive, there seems to be agreement that 2016 in the English-speaking world was defined by "populist" phenomena: the "Brexit" vote in Britain and the election of Donald Trump in the U.S. For the moment, then, populism will be defined in terms of these movements, as they are understood by political scientists. Jan-Werner Mueller is a German scholar who offers a refined definition of populism, based on his recent book, in the London Review of Books. He dismisses the most popular definition of populism by stating that "Not everyone who criticizes elites is a populist....populists don't stop at protesting against Wall Street or 'globalism.'" In contrast to a leftist ideal of what populism could or should be, Mueller asserts that populism is essentially the opposite of pluralism. "Populists claim that they and they alone speak inthe name of what they tend to call the 'real people' or the 'silent majority,'" he writes, "Populists accuse all other political contenders of being illegitimate....Populists hold that those who don't support them -- or who don't share their sense of what constitutes the 'real people' -- may not themselves properly belong to the people." Mueller's populism is authoritarian if not totalitarian; for populists, he claims, "dissent and opposition are by definition suspect, even outright illegitimate." On that understanding, when he sees Donald Trump tweet that "We will all come together as never before," Mueller perceives "more of a threat than a promise."
Mueller goes on to characterize Trump voters as "a white-identity movement," but let's not go there today. Just from what I've quoted, I think it can be seen that Mueller overstates his case against populism as supposedly exemplified by the Trump movement. For him, populism is clearly on a slippery slope to Nazism because of its exclusivist or supremacist assumptions, but I think something slightly less awful is going on. Let me suggest that populism is less a claim of exclusive national or cultural identity and more an assertion of priority best summarized in the familiar slogan, "America First." We might get a better grip on populism if we accept that its opposite is not pluralism, which would make populism totalitarian, but universalism. In the U.S. at least, Trumpist populism rejects first and foremost the idea that the American people should treat everyone on earth the same way we treat each other; that we should let foreign industry compete with domestic industry by any means necessary; that we should let people from any country settle here; that we should care what happens to people in other countries as if it were happening here to us. This is why populists oppose free trade and neocon foreign policy as well as "multicultural" tendencies at home. The guiding idea is that the first priority of foreign policy and trade policy should be to maximize American interests, understood as the material interests of the American people, and not to fulfill any ideological imperative. Domestically, populism is more likely majoritarian rather than dogmatically authoritarian or totalitarian. Majoritarianism can take authoritarian forms, but it isn't necessarily as hostile to pluralism or multiculturalism as Mueller supposes populism to be. It makes pluralists and multiculturalists uncomfortable just the same, not by challenging their legitimacy, much less their existence, but by insisting that on some level -- electorally, at least, but perhaps culturally as well -- minorities are answerable to the majority, on the assumption that the majority has some right to define what the national culture is -- or to say that there is a national culture -- just as it should define the national interest.
Like other non-liberal mentalities, populism may reject a liberal ideal that is individualist as well as multicultural and asserts that it's your unassailable right as a citizen to be yourself, whether that means identification with something other than the majority or traditional culture or an idiosyncratic self-fashioning in defiance of any cultural norm. By rejecting this ideal a populist doesn't necessarily see nonconformists or self-conscious minorities as traitors, but he may feel that such people are failing part of their responsibility as citizens. In our time populism seems inevitably to bend right because most of the American left has shrugged off old notions of individual duty, while populism may have assumptions about citizens' duties (rather than their rights) at its core. The first duty for populist citizens, we can guess, is loyalty in action if not thought to a nationality that is concrete and specific, made up of real people who have a claim on their fellow citizens prior to the imagined claims of humanity. Such a claim offends those who see no contradiction between love of country and love of humanity and thus see populism imposing a zero-sum choice on them at humanity's expense. I don't assume that a populist can't be a humanitarian, but I'd guess that populists see love of country and love of humanity as separate kinds of love that should not be confused with one another to the point of disproportion. If they seem sometimes like ignored or cuckolded spouses in their anger at those who dismiss or disparage their claims, then you're probably getting closer to the essence of populism than many academics do. There's nothing automatically authoritarian about such attitudes, but the attitude comes with an assumption that you don't really have a right to ignore it, and for some people that's just as bad.