It is commonly understood that as a matter of federal law, states' substantive policies may diverge in respect of those matters that are not violative of the United States Constitution. As a practical matter, however, what degree of political heterogeneity among states is possible vis-a-vis substantive policies that are not unconstitutional? The answer to the question turns in large part on whether states, if they so choose, can regulate their citizens even when they are out-of-state. If they cannot, citizens can bypass their home state’s laws by simply traveling to a more legally permissive state to do there what is prohibited at home, hindering a state's capacity to accomplish constitutional objectives. Consider the example of legislation banning assisted suicide: the state interests most likely are undermined if its sick citizen takes a bus to a jurisdiction that allows her to end her life there.
Many courts and noted commentators have concluded that states cannot bar their traveling citizens from doing in a sister state what the sister state permits its own citizens to do. This Article shows that this view is incorrect. A careful analysis of the many constitutional provisions that bear on extraterritoriality - due process, the right to travel, Article IV's privileges and immunities clause, and the dormant commerce clause - demonstrates that states have significant powers to regulate their citizens' out-of-state activities for the purpose of ensuring the efficacy of constitutional state policies. The Article's purpose is not to show that states necessarily should extraterritorially regulate, but to correct the widespread misperception that the United States Constitution forbids states from so doing. Whether to extraterritorially regulate is a policy decision that states must make on the merits.
The existence of such extraterritorial powers not only inures to the benefit of those states that desire to maximize their laws' efficacy, but is important from a broader systemic perspective. A federal system in which states did not have such extraterritorial powers would systematically disfavor regulation, undermine states' abilities to pursue paternalistic and norm-shaping goals, undercut states' powers to protect third-party interests, and limit the scope of possible experimentation across states. For these reasons, the existence of state power to extraterritorially regulate their citizens secures the possibility of rich political heterogeneity across states.
Mark D. Rosen,
Extraterritoriality and Political Heterogeneity in American Federalism,
U. Pa. L. Rev.
Available at: https://scholarship.kentlaw.iit.edu/fac_schol/519