This paper outlines an account of political realism as a form of ideology critique. We defend the normative edge of this critical-theoretic project against the common charge that there is a problematic trade-off between a theory’s groundedness in facts about the political status quo and its ability to envisage radical departures from the status quo. To overcome that problem, we combine insights from theories of legitimacy by Bernard Williams and other realists, Critical Theory, and analytic epistemological and metaphysical theories of cognitive bias, ideology and social construction. The upshot is an account of realism as empirically informed critique of social and political phenomena. We reject a sharp divide between descriptive and normative theory, and so provide an alternative to the anti-empiricism of some approaches to Critical Theory as well as to the complacency towards existing power structures found within liberal realism, let alone mainstream normative political philosophy, liberal or otherwise.