The theme of political parties is a chapter in the theory of government and political freedom, although democratic theory has traditionally been silent on parties or has approached them as necessary evil. This paper intends to reclaim the normative and functional meaning of political party in representative democracy by showing how it connects to representative democracy and political freedom. It makes this claim by revisiting the ideas of two seminal authors, Carl Schmitt and Hans Kelsen, and reads their work exclusively in relation to political parties and party pluralism, topics it treats as the mirror of their respective conceptions of the state and parliamentary government, and ultimately as a test of the role of political conflict in democracy. The place of political party in the conception of the state and democracy allows us to detect two paradigms of sovereignty depending on whether the party has been approached from the angle of the state or that of citizens, of authority or of freedom. The paper sketches these two lines of interpretation through a selective reading of Schmitt’s and Kelsen’s works in relation to political party in the years of the Weimar republic’s construction. The analysis of the ideas of these two authors proves that the party is more than a pragmatic tool. Like a kaleidoscope, it brings an array of conceptions of politics and the state to the floor and shows to be central in the making of democracy.