Well known as a theorist of law as well as the main drafter of the 1920 Austrian Constitution, Hans Kelsen's contribution to political theory has been paid considerably less attention. Yet not only do his writings on politics offer a significant picture of the 1920s political dilemmas of both the German Weimar Republic and post-war Austria, they also can be of considerable importance for contemporary political theory in as far as Kelsen opens up new perspectives on the links between ethical principles and political institutions. Political institutions rest on ethical principles that define the legitimate expectations that citizens nourish towards them. Such a relationship becomes manifest when claims are raised in public communication. The article aims to sketch the key aspects of Kelsen's political theory, to highlight the historical context in which it was developed, and to highlight the insights that it promises for current political research.