The effects of old and new media on governing and executive leadership have remained curiously under-studied. In the available literature, assessments prevail that consider the media to have developed a strongly power-enhancing effect on incumbent chief executives. A careful reconsideration of mass media effects on the conditions and manifestations of political leadership by presidents and prime ministers in different contemporary democracies suggests that the media more often function as effective constraints on leaders and leadership. Overall, the constraining effects of the traditional media have been more substantial than those generated by the new media. While there are obvious cross-national trends in the development of government–mass media relations, important differences between countries persist, which can be explained to some considerable extent by the different institutional features of contemporary democracies.