We are having a Weimar moment. We have been having one for a while. The Weimar Republic rose in 1919 after the defeat of the German Empire. It fell in 1933 to the Nazi dictatorship. In its 250th year, America shows early symptoms of Weimarization. Amid the legitimation of political violence, street mobilization, runaway debt, and a “stab-in-the-back” legend of racial grievance against the Jews, the political class is divided between those trying to control the chaos and those trying to ride it into power.

It’s a Weimar world out there. One morning in mid-May, I stood on a chair outside a cafe on London’s Strand and watched as a sea of marchers flooded the broad avenue as far as the eye could see. The “Unite the Kingdom” march was organized by Tommy Robinson, an erstwhile soccer hooligan who, in a picaresque transformation familiar from 18th-century novels, has become an articulate and popular representative of “populist” discontent with mass immigration.