Abstract: Constitutional democracies control the exercise of emergency powers through law and through politics. Although many believe that legal controls on the exercise of such powers are essential, examining the structure and history of political controls on emergency powers demonstrates that there are conditions under which such controls can be more effective than legal controls, even in systems committed to parliamentary supremacy. Political controls can sometimes be deployed effectively more quickly than legal ones can. Even in settings seemingly quite unfavourable to the development of constraints on the flow of power to executive government during emergencies, political controls can work, and sometimes might work in real time more effectively than judicial controls do in real time.