This innovative and timely book explores how referendums manage the tension between liberalism and democracy, and whether this decision-making device holds promise for reconciling these two commitments. Featuring an outstanding cast of scholars from around the world, the contributors expose how referendums may be abused on one hand to achieve short-term political or even personal gains, and how, on the other, they may aspire to reflect the best traditions of deliberative, inclusive, democracy-enhancing popular choice. The possibility of democracy-enhancing uses and anti-democratic abuses of referendums reveals a paradox: mechanisms of democracy can be exploited to do violence to the basic principles of democracy. We seek in this book to identify standards we might use to assess the democratic legitimacy of a referendum when we cannot rely on the norms of traditional liberal democracy. Structured around three big questions, this book seeks to identify what makes a referendum legitimate. First, why have referendums on issues of fundamental political importance become so frequent around the world? Second, who are—or who should be—the people that make decisions about a political community’s future? And third, are referendums an effective and reliable mechanism of popular sovereignty or democratic choice? Written for scholars, public lawyers, political actors and citizens, this book brings together diverse perspectives on referendums, constitutionalism, liberalism and democracy in ways that challenge the conventional wisdom, prompt new answers to enduring questions, and urge reconsideration of how we evaluate the legitimacy of referendums.