Last week, the Tenth Circuit issued a decision on Oklahoma’s “Sharia Law Amendment.” A quick summary for those who haven’t followed: In 2010, Oklahoma voters approved a ballot initiative that amended their state’s constitution to prohibit Oklahoma courts from “considering or using” either “international law” or “Sharia Law” in making judicial decisions. A district court issued a preliminary injunction that at least temporarily prohibited the law from taking effect on the ground that its language regarding Sharia Law violates the Establishment Clause. The Tenth Circuit decision held that the district court did not abuse its discretion in issuing the injunction.
Although not yet addressed by the courts, I think it’s worth noting that the Amendment’s language on international law may also be unconstitutional. The reason is the Supremacy Clause. First note that the Amendment explicitly prohibits Oklahoma courts from “considering or using” international law in the form of both treaties and custom. This prohibition is unqualified, and thus at least facially encompasses treaties and custom of all kinds.
Now consider the text of the Supremacy Clause. Article VI, Section 2 of the U.S. Constitution establishes that “all Treaties made, or which shall be made, under the Authority of the United States, shall be the supreme Law of the Land.” By referencing treaties that are “made, or which shall be made, under the Authority of the United States,” the Clause establishes supreme status for treaties to which the United States is a party.
The argument for the Sharia Law Amendment’s unconstitutionality is pretty straightforward. Insofar as it refers to treaties without qualification and thus includes those to which the United States is a party, the Amendment bars Oklahoma courts from considering or using treaties that have the status of supreme federal law. To prohibit a ratified treaty’s consideration or use is to deny its legal relevance, in effect even its existence, regardless of how significantly the treaty might otherwise affect the outcome of a case. Even litigation outcomes directly at odds with those dictated by U.S. treaties would seemingly be permissible in Oklahoma.
There’s also a Supremacy Clause argument concerning the Amendment’s language on customary law. International custom binds all states that have not timely objected to its development, and thus as a formal matter generally binds the United States. Although recently a subject of pretty heated debate, the traditional view is that such custom is a form of federal common law and thus backed by the Supremacy Clause. If one accepts that view, then it would be unconstitutional for the Amendment to bar Oklahoma courts from considering or using custom in much the same way that it would be unconstitutional to bar their consideration or use of U.S. treaties.
A court might attempt to avoid these problems in a couple of ways. The first would be to narrowly construe the Amendment. There is a fair argument that the text pertains only to treaties to which the United States is not a party, and to custom not applicable to the United States. Certain language, for example, suggests a general intent to adhere to federal law—a body that obviously includes U.S. treaties and at least arguably includes customary norms. Other language states an opposition only to the application of the “legal precepts of other nations or cultures.” The latter does not implicate ratified treaties or binding custom, which are the law of this country. The narrow interpretation would alleviate the Supremacy Clause problem by ensuring that the Amendment’s prohibition applies only to treaties and custom that are not federal law.
Another potential way to save the Amendment from unconstitutionality would be to conclude that custom is simply not a form of federal common law. This position would be contrary to the traditional view, but it has gained at least some support since Professors Curtis Bradley and Jack Goldsmith first articulated it in the late 1990s. If customary law is not federal common law, then the Supremacy Clause does not encompass it, and Oklahoma courts would not be obliged to consider or use it in their decisions.
Both of these efforts to save the Amendment would encounter difficulties, however. First, the narrow interpretation would render the Amendment’s text on international law essentially irrelevant in practice. I doubt that Oklahoma courts encounter many cases requiring them to resolve disputes concerning U.S. treaties, much less treaties to which the United States is not even a party. I also doubt they encounter many opportunities to resolve disputes over obscure principles of international custom that do not bind the United States. And as long as that is true, the narrow interpretation would essentially tell the courts not to do something that they don’t do anyway.
Second, concluding that international custom lacks the status of federal common law would require a departure from the traditional doctrine on that issue. There are, frankly, pretty intriguing arguments on both sides of the debate that the Bradley and Goldsmith argument has generated, but the U.S. Supreme Court has never squarely held that international custom lacks the status of federal common law.
In short, the constitutionality of the Sharia Law Amendment’s language on international law is, at best, uncertain. Its treatment of treaties is either unconstitutional or essentially irrelevant. And its treatment of custom may require courts to resolve a longstanding debate about custom’s domestic status.