Fascism is back in fashion — at least if mainstream political commentators are to be believed. Many have been quick to seize upon the oft-misunderstood term to describe Donald Trump, presenting the Republican presidential candidate as a uniquely menacing figure along the lines of Franco or Mussolini.

But this careless use of the fascist label ignores the historical roots of fascism and sidesteps the vital work of carefully analyzing Trump’s political ascendance. It also undermines efforts to develop a serious understanding of the phenomenon of fascism itself.

Dylan Riley — a professor of sociology at the University of California-Berkeley and member of the New Left Review editorial board — has spent years developing an understanding of fascism that is rooted in the history of actual fascist movements.