Political philosophy often focuses on “major institutions” that make up the “basic structure” of society. These include political, economic, and social institutions. In this paper I argue first that policing plays a substantial role in generating the kinds of inequalities and problems that are concerns of social or structural justice, and therefore that police agencies qualify as a major institution. When we abandon full compliance or similar idealizations, it is clear that policing is not a concern secondary to, e.g., the electoral system or the scheme of property rights in a society. Nor, I argue, does maintaining full compliance or moral character idealizations obviate an active enforcement role. Eliminating that role from an idealized model society requires engaging in a methodologically and substantively unattractive amount of abstraction. The result is that an active enforcement role is at the core of a complete theory of justice rather than something that is significant only “downstream” from more fundamental issues.