Radbruch was a member of the Social Democratic Party of Germany (SPD), and held a seat in the Reichstag from 1920 to 1924.
In September 1945, Radbruch published a short paper Fünf Minuten Rechtsphilosophie (five minutes of legal philosophy), that was influential in shaping the jurisprudence of values (Wertungsjurisprudenz), prevalent in the aftermath of World War II as a reaction against legal positivism.