CONGRESS, ARTICLE IV, AND INTERSTATE RELATIONS Gillian E. Metzger TABLE OF CONTENTS INTRODUCTION ..........................................................................................................................1470 I. THE STRUCTURAL DEMANDS OF UNION: THE CASE FOR BROAD CONGRESSIONAL POWER OVER INTERSTATE RELATIONSHIPS...............................1478 A. Congressional Power To Authorize State Violations of the Dormant Commerce Clause...............................................................................................................1480 B. Congressional Power over Section 2 of Article IV........................................................1485 1. The Overlap of the Commerce Power and the Privileges and Immunities Clause .......................................................................................................1486 2. The Extradition and Fugitive Slave Clauses...........................................................1489 3. Section 2’s Text ............................................................................................................1490 C. Express Support for Broad Congressional Power in Other Constitutional Interstate Relations Provisions .............................................................1493 1. The Full Faith and Credit and Effects Clauses of Article IV, Section 1 .............1493 2. The New State, Territory and Property, and Guarantee Clauses of Article IV, Sections 3 and 4....................................................................................1498 3. Article I, Section 10.....................................................................................................1499 D. Normative and Functional Considerations ...................................................................1501 1. The Positive Value of Interstate Discrimination......................................................1501 2. Institutional Competency ...........................................................................................1503 E. Arguments from History ...................................................................................................1507 F. The Constitutional Model of Horizontal Federalism ...................................................1511 II. LIMITS ON CONGRESS’S POWERS OVER INTERSTATE RELATIONS ........................1512 A. Core Postulates of Horizontal Federalism......................................................................1512 1. State Autonomy............................................................................................................1513 2. State Equality...............................................................................................................1517 3. State Territoriality .......................................................................................................1520 B. Congress, Article IV, and the Fourteenth Amendment.................................................1523 1. Congressional Power and Individual Rights ...........................................................1523 2. Fourteenth Amendment Limits on Congressional Interstate Authority...............1526 3. Saenz v. Roe .................................................................................................................1529 III. APPLICATIONS......................................................................................................................1531 A. DOMA and Congress’s Power Under the Effects Clause .............................................1532 B. CIANA and Congress’s Power over Article IV Privileges and Immunities ...............1536 CONCLUSION ...............................................................................................................................1541 1468 CONGRESS, ARTICLE IV, AND INTERSTATE RELATIONS Gillian E. Metzger∗ Article IV imposes prohibitions on interstate discrimination that are central to our status as a single nation, yet the Constitution also grants Congress broad power over interstate relations. This raises questions with respect to the scope of Congress’s power over interstate relations, what is sometimes referred to as the horizontal dimension of federalism. In particular, does Congress have the power to authorize states to engage in conduct that otherwise would violate Article IV? These questions are of growing practical relevance, given recently enacted or proposed measures — the Defense of Marriage Act (DOMA) being the most prominent example — in which Congress has sanctioned interstate discrimination and other state measures seemingly at odds with fundamental precepts of horizontal federalism. These questions also are significant on a more conceptual level, as they force clarification of the proper relationship between Congress and the Supreme Court in horizontal federalism disputes. This Article contends that the Constitution grants Congress expansive authority to structure interstate relationships and that in wielding this interstate authority Congress is not limited by judicial interpretations of Article IV. Rather than constituting unalterable demands of union, the antidiscrimination provisions of Article IV are best understood, like the dormant commerce clause, as constitutional default rules. These provisions are judicially enforceable against the states, but their enforceability is contingent on the absence of congressionally authorized discrimination. Congress’s power to authorize discrimination has limits; however, those limits derive not from Article IV or principles of federalism, but instead from the Fourteenth Amendment. Constitutional text, precedent, normative and functional concerns, and history all support such congressional primacy in interstate relations. Ultimately, however, the basis for broad congressional interstate authority is constitutional structure. Most of the Article is devoted to a close analysis of these standard sources of constitutional meaning to determine the appropriate parameters of the congressional role in interstate relations. The Article closes with an examination of the practical implications of such a broad view of Congress’s powers, assessing the constitutionality of DOMA and the recently proposed Child Interstate Abortion Notification Act. ––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– ∗ Professor, Columbia Law School. Special thanks to Mike Dorf, Ariela Dubler, Liz Emens, Dick Fallon, Barry Friedman, Heather Gerken, Caitlin Halligan, Tom Lee, Henry Monaghan, Gerry Neuman, Sasha Samberg-Champion, Cathy Sharkey, and John Witt for their insightful comments and questions. This Article also benefited greatly from comments I received from par- ticipants in workshops at Columbia Law School, Harvard Law School, and University of Virginia Law School. Ella Campi, Rachel Rubenson, and Adam Schleiffer provided helpful research assis- tance. 1469 1470 HARVARD LAW REVIEW [Vol. 120:1468 INTRODUCTION Consider three potential federal statutes: • Congress authorizes states to refuse to recognize laws and judg- ments of other states that relate to same-sex marriage. • Congress authorizes states to impose residency requirements as a condition of engaging in certain economic activities within a state, such as the provision of legal services. • Congress imposes civil and criminal penalties on anyone who knowingly assists a minor to obtain an out-of-state abortion without complying with the parental notification requirements of the state in which the minor resides. Each of these statutes authorizes interstate discrimination in some form. Moreover, absent such authorization, each form of discrimina- tion is of dubious constitutionality. Under current case law, state legis- lation refusing to recognize other states’ judgments or requiring resi- dency as a condition of occupational licensure plainly contravenes Article IV of the Constitution.1 Collectively, therefore, these hypo- thetical measures raise questions with respect to the scope of congres- sional power over interstate relations in general and Article IV in par- ticular. Those questions are of increasing practical importance. Conjuring up these statutes requires no great feat of legal imagination. The first, of course, is already enacted law, in the form of Section 2 of the 1996 Defense of Marriage Act (DOMA).2 The third may soon become law; it mirrors Section 2 of the Child Interstate Abortion Notification Act (CIANA), which the House passed in 2005 and which the Senate adopted in the form of the Child Custody Protection Act (CCPA) in 2006.3 Only the second statute is (for now) purely hypothetical. How- ever, measures authorizing interstate economic discrimination — such ––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– 1 See, e.g., Baker v. Gen. Motors Corp., 522 U.S. 222, 232–33 (1998); Supreme Court v. Piper, 470 U.S. 274, 288 (1985). 2 28 U.S.C. § 1738C (2000). 3 See CCPA, S. 403, 109th Cong. § 2 (as passed by Senate, July 25, 2006); CIANA, H.R. 748, 109th Cong. § 2 (as passed by House, Apr. 27, 2005). The 109th Congress ended without agree- ment between the House and Senate on which measure to adopt. Although the two measures are identical in the penalties they impose on out-of-state abortions that violate a resident state’s pa- rental notification requirements, CIANA is significantly broader than CCPA. Section 3 of CIANA, for example, separately mandates parental notice and a minimum twenty-four-hour de- lay for minors obtaining abortions regardless of whether the minor’s home state or the state in which the abortion is