Judicial Supremacy: Explaining False Starts and Surprising Successes

Why has judicial supremacy emerged and endured in some places and not others? That the judiciary is the final arbitrator of constitutional matters is puzzling, as the judicial branch has neither the power of the purse nor direct access to military power. Indeed, although many of the world’s early constitutions betrayed the potential for judicial supremacy, it only took hold in a handful of polities. The United States, where judicial review became preeminent, is the example par excellence. We explain this variation by focusing on the process by which de jure power is originally negotiated and enforced. When judicial independence and judicial review are arrived upon as the solution to a coordination problem by multiple actors whose coercive power is diffuse, rather than imposed from above by a sovereign seeking to tie his hands, judicial supremacy obtains. We test this claim against the history of Magna Carta, U.S. Constitution, and several charters from Medieval Europe.