A new paradigm of political-bureaucratic relations emerged through the 1980s holding that U.S. democratic institutions continuously shape nonelective public bureaucracies. Several empirical studies support the paradigm with evidence suggestive of political manipulation but none reveals the scope or specific mechanisms of political control. We explore the dynamics of political control of the bureaucracy explicitly to determine the scope and mechanisms. We examine output time series from seven different public bureaucracies for responsiveness to political tools applied in the late Carter and early Reagan administrations. We find responsiveness in all seven cases. The evidence also shows that political appointmentsa shared power of the president and Congressis the most important instrument of political control; changing budgets, legislation, congressional signals, and administrative reorganizations are less important. These findings confirm intuitive assertions by institutional scholars and suggest a method of policy monitoring that could enhance future democratic control of the bureaucracy.