AbstractThe battles between proponents and opponents of judicial supremacy have recently intensified in the US and also in Europe. I summarise the debates in political philosophy, legal theory and comparative constitutionalism and argue that both judicial supremacy and parliamentary supremacy claims are empirically and normatively indefensible: no one actually has or should have the last word. Instead, we need adversarial judicial, political and public dialogues stimulated by cooperation/competition between parliaments and courts and other actors. I focus on judicial review in two contexts. I ask whether the Canadian notwithstanding clause might provide a rational way forward, if properly amended. For the EU I analyse new forms of dialogue, cooperation and competition between parliaments and constitutional courts in Member States, the European Court of Justice and the European Court of Human Rights. Learning from these comparisons, I submit, can profit from two non-legal discussions: first on ‘democratising expertise’ in the traditions of critical pragmatism and experimentalist governance and, second, on the traditions of democratic institutional pluralism and associative democracy.