Over the past 10 years, urban regime theory has become the dominant paradigm for studying urban politics in liberal democracies. Yet there is disagreement about how far it can help us to understand urban political processes. This article argues that regime theory is best understood as a theory of structuring with limits in its analysis of the market economy. These limits undermine its ability to explain the importance of political agency—the scope of individual or collective choice in political decisions and the impact of those choices in the evolution of US cities. It is further argued that there are important normative dimensions to urban regime theory, most fully articulated in Elkin’s commercial republic, which academic commentaries have not acknowledged. However, the empirical analysis developed in regime theory contradicts its normative objectives. The absence of a conceptualization of market dynamics, in the light of pessimism about the prospects for equitable regime governance, not only limits it as a theory of structuring but it also renders it unable to explain how the commercial republic can be realized. Regime theory is, therefore, unconvincing for two reasons. It cannot explain how much local politics matter, and it fails to demonstrate that its normative goal—more equitable regime governance—can be achieved, given the realities of the US market economy. Regime theory needs a more developed understanding of structuring. It may be fruitful, therefore, for regime theorists to re-engage critically with variants of Marxism, which unlike Structuralism, recognize the possibility of agency.