This book exposes the possibility for critical engagement with the function of public law and with constitutionalism in its political dimensions. Bringing together the reflections of three leading constitutionalists: Martin Loughlin, James Tully and Frank Michelman, and comprising also three critical commentaries on each, the book addresses the multiple ways in which public law is implicated in the logic of rule. This seems to operate on the one hand in maintaining and underwriting relative patterns of power and weakness through political structures and processes. On the other hand, public law may be considered to contain the potential to redress these patterns through the use of constitutional authority, social and economic as well as civil and political rights, the redistribution of political power, the expansion of territorial governance, and moves to supra-state levels of authority.The book is intended to reproduce in a succinct and organised way the insights into both the limitations and the potentialities of public law within its political setting.