In recent history and within liberal democracies we can bear witness to a growing number of social and political antagonisms that present a challenge to the stability of such orders. Chantal Mouffe identifies the core of the problem in the rationalism of modern democratic strains of thought and centrist political actors. In contrast, Mouffe suggests her own version of agonistic democracy that accepts the political as a sphere of ineradicable antagonism and differenc, but which can also control it to the benefit of liberal democracy. Her understanding of agonism derives from an appropriation of Carl Schmitt’s political thought. A review of Schmitt’s existential against Mouffe’s discursive understanding of the political brings insight in the way in which Mouffe both agrees and distances herself from Schmitt. It also sheds light on key conceptions that form the central claim of agonistic pluralism. It is a truly political theory and system which can preserve the political unity of a modern democratic state in the conditions of constitutive pluralism. Considering deliberative democratic criticism of her theory and through the example of Donald Trumps right wing populism, the author questions this claim and reaffirms the role of deliberation as useful to both Mouffe’s agonistic pluralism and the actual political situation within the United States.