Structural Indeterminacy and the Separation of Powers

Despite ongoing disagreement about how the Constitution allocates powers among the different branches, the two dominant schools of thought in American separation-of-powers debates—formalism and functionalism—agree on three premises: Certain powers inhere in certain government branches, some powers are vested exclusively in one or another branch, and the judiciary is the final arbiter of separation-of-powers disputes. Disagreement is largely about how powers should be parsed and which should be shared. Yet over the long lifespan of our constitutional tradition, momentous doctrinal upheavals are relatively commonplace. This Article describes four tectonic shifts in separation-of-powers doctrine: Founding-era debates about how to define and blend powers, nineteenth-century debates about the constitutionality of the nascent civil service, Lochner-era debates about legislatures’ authority to define and regulate public utilities, and mid-nineteenth-century debates about the sources of international law.