Recall business and media figures cultivating anxiety and furor over demographic change. These incidents only scratch the surface of this ascendant idea: Popular and ruling politicians in every region of the world have been expressing some version of great replacement theory, eroding democratic norms in the name of preventing demographic change and restoring national greatness.

What is great replacement theory? Variations on the theory have existed for centuries, but it was given this name by a French novelist in 2011 who believed Black and Brown immigrants were “invading” Europe, brought by shadowy elites to “replace” Europe’s White population. From there, politicians and theorists—whether in the United States or the United Kingdom, Germany or Chile, Hungary or Australia—repackaged the conspiracy as a story of “globalists” welcoming “migrant criminals” and diversity initiatives to take away the jobs, cultures, electoral power, and the very lives of White people. Over time, great replacement theory has expanded the threat to include citizens, men, Jews, Christians, heterosexuals, and ethnic majorities in countries as distinct as Russia, El Salvador, Brazil, Italy, and India. All are targeted with the message that they are under an existential attack that only a strongman can prevent.