State medical boards are increasingly responsible for regulating medical and osteopathic licensure and professional conduct in the United States. Yet, there is great variation in the extent to which such boards take disciplinary action against physicians, indicating that some boards are more zealous regulators than others. We look to the political roots of such variation and seek to answer a simple, yet important, question: are nominally apolitical state medical boards responsive to political preferences? To address this question, we use panel data on disciplinary actions across sixty-four state medical boards from 1993 through 2006 and control for over-time changes in board characteristics (e.g., composition, independence, budgetary status), regulatory structure, and resources. We show that as state legislatures become more liberal [conservative], state boards increasingly [decreasingly] discipline physicians, especially during unified government and in the presence of highly professional legislatures. Our conclusions join others in emphasizing the importance of state medical boards and the contingent nature of political control of state regulation. In addition, we emphasize the roles that oversight capacity and strategy play in offsetting concerns regarding self-regulation of a powerful organized interest.