Fascism was No. 3 last year, between socialism and racism, which is just where fascism began in the 1920s. Now, many political commentators, especially on the left, detect a fascist moment in the Western democracies. But is fascism an accurate heuristic for the populist movements in the United States and Europe that have arisen in recent years, or is invoking the term just a kneejerk way of condemning political opponents? And if it’s inaccurate, might the word still represent a useful case study on the debased value of political language?

The problem, as they might say at Merriam-Webster, is in the definition. Scholars of fascism do not agree on what fascism means; nor, for that matter, do fascist scholars. The difficulty is twofold, and concerns both origins and actions.

Fascism originated in 1920s Europe, mostly among the radical collectivists of the left. But it developed by synthesizing command economics with the racism and nationalism of the radical collectivists of the right. Historians now discount the once-popular Marxist interpretation that fascism was the child of capitalism and imperialism. But they are not unanimous about whether the rivalry of fascism and communism was a sibling rivalry. Like the communists, the fascists were radically unprincipled opportunists, contemptuous of democratic norms. They sought to overthrow the right-left format of democratic politics, and their ideology combined elements of both.

The second problem, also related to fascism’s deliberate immoralism, lies in identifying the nature of fascist rule. Was Nazi Germany the quintessential fascist state, or a unique exception to the rule? The numerous fascist states of southern Europe and South America ended not in apocalypse, but repressive tedium. Most fascist economies followed Benito Mussolini’s definition of fascism as the corporatist control of private industry by government, but most fascist states also tended to annex areas of the economy to government control. And how much did fascist governments deliver on their promise to create autarkic, self-sufficient economies? Again, the historians are not in agreement here.

Perhaps the best definition comes from Robert Paxton, professor emeritus at Columbia University and holder of the Legion d’Honneur, despite all the books he has written on wartime France’s pro-Nazi Vichy regime. Paxton’s The Anatomy of Fascism analyzes the stages by which 20th century fascisms rose and fell. It should be essential reading for any student of fascist movements, and especially for anyone thinking of founding one.

Fascism, Paxton says, is a dynamic process, rather than a fixed ideology like socialism or communism. There are five steps on Paxton’s road to hell, and not all fascist parties made it past the second step:

Ideological formation and the creation of a party with quasi-military cadres. Talk of national humiliation, lost vigor, and the failures of liberalism and democracy. Entry of the party into national politics. Intimidation of rivals, and planned acts of “redemptive violence” against suspect minorities and radical rivals. Arrival in government, often in alliance with conservatives. Exercise of power, in concert with institutions and business. The regime expands its control at home: restricting the press and democratic processes, corporatizing business, and collectivizing the people. Abroad, it asserts itself militarily. Radicalization or entropy: Some fascists go down in a Götterdämmerung, but most die of boredom.

Elements of Paxton’s early stages appear in the angry populism that is gaining ground in modern Western democracies, especially in hostility toward Muslim immigrants and the austerity measures of the post-2008 eurozone. There are politicians whose parties are of fascist extraction, like the National Front in France, whose Catholic-tinged identity politics can be traced back to proto-fascists like the early 20th century Action Francaise. Some of these politicians and parties, like Norbert Hofer’s Freedom Party in Austria, remain closer to their roots than others, and might merit the name neofascist. Others are doing their best to shed the worst of these associations as they enter mainstream politics; the National Front’s Marine Le Pen, for example, is no longer on speaking terms with her father Jean-Marie, the National Front’s founding ideologue. But only one Western democracy, Greece, has a fascist party like Golden Dawn, which possesses both uniformed street fighters and members of the national parliament. When Europe’s “New Right” leaders are called fascists in suits, it’s an acknowledgment that they are not fully fascist. Real fascists wore uniforms.