Ralph Hoffroge, a historian at the University of Potsdam, is author of Working-Class Politics in the German Revolution: Richard Müller, the Revolutionary Shop Stewards and the Origins of the Council Movement (Haymarket 2015), A Jewish Communist in Weimar Germany The Life of Werner Scholem (1895–1940) (Haymarket 2018), and has edited, with Norman LaPorte, Weimar Communism as Mass Movement, 1918–1933 (Lawrence & Wishart 2017).