The Article makes seven points in relation to this question. Its observations are relevant not only to the unlikely event of Roe’s demise, but also to a non-trivial class of constitutional state laws that can be circumvented if a citizen can cross his state border and avail himself of his neighboring state’s less restrictive laws. This class includes restrictions on gambling and assisted suicide, mandatory motorcycle helmet laws, and even laws regulating agricultural goods.

The first four points are doctrinal. First, contrary to many people’s strong intuitions, states in our country’s federal union generally do have the power to regulate their citizens’ out-of-state activities. Second, although states enjoy general extraterritorial regulatory powers, particular regulations can run afoul of constitutional principles concerning interstate relations that are found in the right to travel, Article IV’s Privileges and Immunities Clause, and the Fourteenth Amendment’s Privileges or Immunities Clause. Third, Utah’s effort to regulate Mary would not be precluded under any of these doctrines as they currently are understood by the United States Supreme Court. Fourth, current doctrine nevertheless cannot be presumed to be stable because, among other reasons, there has not been a sustained practice of such state extraterritorial regulations that has received attention from legislatures, the public, and the courts.

The remaining three points are normative and institutional. The fifth point is that answering the doctrinal question of whether Utah can regulate Mary’s California travels invariably will turn on normative considerations because the question is not answered by clear constitutional text, longstanding tradition, or precedent. The sixth point clarifies the normative question that is presented by Utah’s regulatory attempts in relation to Mary. It also demonstrates that whether Utah should have such extraterritorial powers is an exceedingly difficult question that goes to the heart of the meaning of state citizenship and national citizenship and, ultimately, to the nature of our country’s federal union.

Why? It is widely recognized that, with regard to those policies that neither the Constitution nor federal statutory law demands national uniformity, states may take different regulatory approaches. Not infrequently, however, a state will be unable to accomplish its constitutionally legitimate goals if its citizen can free herself of her home state’s regulation simply by walking into a state that does not so regulate. If states does not have the power to regulate so as to preclude “travel-evasion” of their constitutional policies, then the extent of the pluralism of state policies possible under our federal union is, as a practical matter, quite limited in relation to the non-trivial class of policies that are vulnerable to travel-evasion. Call this a regime of “soft” pluralism. By contrast, a federal system in which Utah can prohibit Mary from obtaining an abortion in California would be a regime of “hard” pluralism in which states can efficaciously regulate across the entire range of matters with respect to which federal law does not demand nationwide uniformity.

To be clear, this Article does not seek to definitively resolve the choice between “soft” and “hard” pluralism, but only aims to show that the choice is a difficult one and that much rides on how the question is resolved. The Article’s seventh, and final, point is largely institutional: what societal institutions should make the choice between “soft” and “hard” pluralism? Though the Article’s doctrinal analysis establishes that our country presently has a regime of “hard” pluralism in which each state generally can choose whether it wishes to extraterritorially regulate its citizens, point seven makes clear that these state decisions may be legislatively reversed by Congress. Congress has the power to determine the scope of state extraterritorial powers under the Full Faith and Credit Clause’s “Effects” Clause, Section Five of the Fourteenth Amendment (in relation to what qualifies as a privilege or immunity of national citizenship), the Commerce Clause, and possibly Article IV’s Privileges and Immunities Clause. Point seven further argues that Congress properly has a privileged role in answering such questions because it has institutional advantages vis-a-vis both states and the federal courts in deciding the scope of state extraterritorial regulatory authority and in thereby determining the nature of state and federal citizenship and the resulting character of our federal union.

The Article brings together the case law that creates nonuniformity across geographical locations. It first explains the mechanics by which this "geographical constitutional nonuniformity" is generated and establishes that such nonuniformity sometimes is used to enable idiosyncratic but valuable communities to endure. Nonetheless courts often overlook the availability of geographical constitutional nonuniformity and unquestioningly conclude that the Constitution forecloses any and all communities from governing themselves in unconventional ways. The Article shows how geographical constitutional nonuniformity can be utilized to extend the powers of self-governance to various communities not currently the beneficiaries of constitutional nonuniformity and identifies the factors that determine when resort to nonuniformity is constitutionally appropriate.

The mechanism for self-governance proposed and explored here - the delegation of circumscribed interpretive authority of select provisions of the United States Constitution to a limited number of community-based courts - is not as unprecedented as it might at first sound. It is very similar to the powers exercised by Native Americans in tribal courts. Each tribe's courts are authorized to provide their own interpretations of due process, equal protection, search and seizure, and the like, with no review from federal courts in virtually all cases. As a result, due process means one thing in San Diego, another in the 25,000 square miles of Navajo land, and yet something else on the Nisqually reservation.

In an earlier article I analyzed the many benefits of the regime of community-based courts in Indian country. See Multiple Authoritative Interpreters of Quasi-Constitutional Federal Law: Of Tribal Courts and the Indian Civil Rights Act, 69 Fordham L. Rev. 479 (2000). Such a regime permits the creation of unique doctrines and governmental institutions that support Indian culture, and the avoidance of doctrines and institutions that actively undermine it. Yet as the regime sustains cultural heterogeneity, it simultaneously helps to create a common nation-wide culture insofar as all tribes are interpreting the shared text of American constitutional principles. In short, allowing diverse communities the opportunity to construe authoritatively a shared text holds out the possibility of creating commonality without commanding homogeneity. It is an approach that is consonant with one of the federal system's chief objectives of uniting without snuffing out diversity.

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.