Deconstructive Constitutionalism explores the relationship between the thinking of Immanuel Kant and Jacques Derrida concerning modern constitutionalism. Kant is widely recognized as one of the philosophical forebears of modern constitutionalism, that is, the notion that state powers should be defined and limited through a constitution. Kant laid the foundation of constitutionalism through his exposition of freedom, practical reason, and moral law. However, constitutionalism is under severe strain due to the challenges posed by inter alia climate change, global health, global conflict, authoritarianism, authoritarian populism, religious fundamentalism, migration, and inequality. Deconstructive Constitutionalism investigates, by way of Derrida's engagements with Kant, how the foundations of constitutionalism can be conceived differently to address some of these twenty-first-century challenges. The book examines the possible implications of such a re-reading of Kant for democracy, the human-animal relation, criminal law and punishment, as well as for a global constitutional order.