Ps filed suit against D seeking injunctive relief and alleging that D violated the Sherman Act. D had obtained federal funds to help build a sewage treatment facility within the Eau Claire Service Area, that included P; the facility is the only one in the market available to Ps. D has refused to supply sewage treatment services to P. It does supply the services to individual landowners in areas of the Towns if a majority of the individuals in the area vote by referendum election to have their homes annexed by D. Ps alleged they were potential competitors of D and that D used its monopoly over sewage treatment to gain an unlawful monopoly over the provision of sewage collection and transportation services. The Court ruled for D; Wisconsin's statutes regulating the municipal provision of sewage service expressed a clear state policy to replace competition with regulation. The court of appeals affirmed. The Supreme Court granted certiorari.