The Taft Lecture: Living Under Someone Else's Law

This paper explores the differences between vertical and horizontal federalism. Vertical federalism is so familiar that we can recite the reasons to value states’ role in our federal system as easily as children recite the alphabet. The law of horizontal federalism, in contrast, has mostly developed within its doctrinal silos - the Dormant Commerce Clause, personal jurisdiction, the Full Faith and Credit Clause.This papers makes two points. First, it’s both strange and instructive that the two halves of “Our Federalism” have developed so differently given that they are both preoccupied with the same problem: what happens when one government invades another’s turf? Vertical federalism offers a single narrative for adjudicating federal-state relations. We ask the same question in every case - how should we think of federal-state relations writ large? - and unsurprisingly gets the same answer in every case. Horizontal federalism, meanwhile, resolves state-federal tussles issue by issue, problem by problem, domain by domain. Rather than focusing on a single big question - how should we think of state-state relations writ large? - it emphasizes context and facts on the ground and a myriad of doctrinal questions writ small. It thus lacks what vertical federalism theory has long provided: a broad-gauged account of how our governing institutions ought to interact. Second, if we’re going to build an overarching narrative for horizontal federalism, it shouldn’t be the story scholars have offered thus far. The moral of that story is that no one should be forced to live under someone else’s law. But that tale is premised on an outdated attachment to state sovereignty and an unrealistic impulse to tamp down on state spillovers. The paper thus sketches an alternative, democratically inflected account that we should deploy going forward.