This book defends constructivism as a leading approach to formulating the moral basis of political authority. It addresses a central tension in constructivist theory: how principles can be both dependent on human deliberation and normatively objective. Moving beyond the familiar Rawlsian model, Political Authority develops a constructivist framework for normative political analysis that is accommodating of pluralism, sensitive to context, attuned to moral reasoning, and continuous with a long history of political thought about the nature of moral truth and legitimacy in politics. Engaging with traditional themes of authority, power, and justice, as well as contemporary debates on political realism, public justification, and performance legitimacy, this book is of interest to scholars and graduate students in political philosophy, political theory, normative ethics, democratic theory, and human rights studies.