Consider an abstract political economy which has a collective choice rule together with strategic interactions among players. We prove that there exists an equilibrium in such an economy by synthesizing an equilibrium existence theorem in generalized games by Shafer and Sonnenschein (1975) and a voting core existence theorem in simple games by Schofield (1984, 1989). The theorem can be applied to a public good economy where public good provisions are determined by a class of voting rule.