The interrelationship between the federal and state courts is one of the most arcane and yet most fascinating aspects of the American experiment. After more than twenty years as a state judge, I remain amazed by how hard both Congress and the federal courts work to discern and preserve the appropriate sphere for state judiciaries. While the broad sweep of American history has seen increasing concentrations of power in both the federal executive and legislative branches at the expense of their state counterparts, I would argue that no similar accretion of power has occurred in the courts. One need only read the jurisdictional statutes of Title 28 of the United States Code, or peruse the table of contents of a few volumes of the Wright and Miller treatise,1 to see the enormous energy that federal government actors have expended to maintain state court viability.
Why has the federal government not, in the course of two hundred years, arrogated to itself a greater share of the judicial power? Why is more than ninety-eight percent of the nation's judicial business still conducted in state courts, and only two percent in the federal courts? And why are many of the "biggest" cases, if bigness be measured in amounts of damages sought or size of judgments awarded, tried in state courts? The answer, T submit, is to be found not in the generous nature of federal authorities, past or present, but in the fact that state courts, unlike state governors or state legislatures, are actually part of the federal judicial system. As Alexander Hamilton observed in The Federalist No. 82:
[T]he national and State systems are to be regarded as ONE WHOLE. The courts of the latter will of course be natural auxiliaries to the execution of the laws of the Union, and an appeal from them will as naturally lie to that tribunal which is destined to unite and assimilate the principles of national justice and the rules of national decisions.2
And as one whole, both state courts and federal courts have, since the inception of the Republic, applied and developed international law. The constitutional framers could have structured the government so that most of this authority would lodge in the federal system, but they declined to do so. Congress could have used the jurisdictional grant in the Constitution to place most international questions in federal court, but it has likewise declined to do so. Thus the state courts remain vital partners in the interpretation and application of both formal and customary international law. Whether the state courts' role will increase or decrease in the future is a fascinating question, and one which may turn on the extent to which courts retain a primary role in developing and applying international law.
I will first examine the compromise that enabled state courts to make binding decisions based on federal and international law as well as the law of their own states. I will then discuss the application by state courts of customary international law and recount the judicial response to whether Erie has restricted the role of federal courts in this area. Next, I will discuss recent Texas cases dealing with treaties and international conventions. Finally, I will pose some questions about the future of international law in state courts.
II. THE CONSTITUTION'S ALLOCATION OF POWER BETWEEN STATE AND FEDERAL COURTS IN INTERNATIONAL LAW CASES
After America won its independence, each state operated a separate court system, with nine of the thirteen having some kind of separate court of last resort rather than a legislative high court.3 These state courts were viewed by outsiders as parochial institutions, favoring their own residents against those of other states and, of greater significance to our discussion, those of other countries. The Continental Congress could pass resolutions protesting injustices, but little more,4 as the only jurisdiction given to the national courts was for "the trial of piracies and felonies committed on the high seas" and "appeals in all cases of captures. …