Many American fascist groups arose in the 1930s out of the Northern Ku Klux Klan (KKK) of the 1920s. We can see the continuity by using British socialist theorist Raymond Williams’ concept, a “structure of feeling.” The 1920s KKK targeted Catholic, Jewish, and other non-white Protestant immigrants – though never abandoning its anti-Black racism – and the fascists narrowed their target to Jews alone, but common to both was the construction of fear and then anger. Yet a fundamental difference between the Klan and the fascists is equally important: the Northern Klan was a mass, largely nonviolent movement that won major victories by relying on electoral politics, while the small fascist groups used violence as their primary tactic. Too often “fascism” has been used as a condemnation without specific content. Examining the Ku Klux Klan and the fascists side by side and focusing on what fascist groups did can yield better analyses. While there are commonalities among fascists in different contexts and different historical moments, the term is most useful when understood as a “cluster concept”: a cluster of ideas, values, and actions not all of which will be found in each exemplar of fascism.