Antisemitism in the political left was a topic long before 1945. The criticism of it is as old as the issue itself. During the Weimar Republic, former founding members of the KPD like Franz Pfemfert and anarcho-syndicalists like Rudolf Rocker criticized the anti-Semitic agitation during the Schlageter course. In the mid-1920s, Clara Zetkin warned at the KPD party congress about anti-Jewish sentiments at the grassroots level. In 1929, one of the first radical critiques of the KPD's anti-Zionism appeared in the central organ of the KPD opposition formed around Heinrich Brandler and August Thalheimer. With their critique, the anarchist and communist left connected to interventions by Rosa Luxemburg and Leo Trotsky while also reflecting on the developments in Russia after the Bolshevik Revolution. Marx's claim to overturn all conditions in which man is "an abased, a enslaved, a forsaken, a contemptible being" included the fight against anti-Semitism within their own ranks.