This paper suggests a theoretical re-reading of populism. Usually dismissed as a pathological form of politics, it deals with borders of political system and raises important issues to democratic theory. Koselleck’s notion of modern political semantics helps to reframe the discussion of the ambiguous meaning of this term and introduce to philosophical interpretations of this concept. Drawing from heterogeneous philosophical material (especially, theory of power of Claude Lefort and theory of People of Jacques Rancière), it is argued that the problem of populism arises when a particular form of collective ensemble, the people, is asked to open up for prospect of democratic expectations. Populism thus acquires an ambivalent position by articulating contemporary political reason.