This paper presents and defends an account of how the political power of business corporations under-mines liberal forms of legitimacy. Corporations are cre-ated and empowered by the authority of the liberal state. Under capitalism, the logic of competitive ad-vantage dictates that those powers be applied in ways that violate, directly and indirectly, basic liberal norms and values. That violation supplies reasons to contest the political order authorizing their occurrence. Cor-porate power therefore represents a failure of the lib-eral order to satisfy its own conditions of legitimacy.