Zachary D. Kaufman, Yale University Law School, has published From the Aztecs to the Kalahari Bushmen -- Conservative Justices' Citation of Foreign Sources: Consistency, Inconsistency, or Evolution? in volume 41 of the Yale Journal of International Law Online (2015). Here is the abstract.
This essay, authored by Dr. Zachary D. Kaufman, is published in the online companion of the Yale Journal of International Law. On April 28, 2015, there were few surprises at the Supreme Court. During oral argument in Obergefell v. Hodges, counsel for each side mostly rehearsed the usual marriage equality arguments around rights, dignity, fairness, love, procreation, family, tradition, religion, and slippery slopes. Almost two months later, on the historic day of June 26, the Supreme Court announced its decision in Obergefell. The 5-4 majority opinion held that the Fourteenth Amendment requires states both to license marriages between two people of the same sex and to recognize such marriages if lawfully licenses and performed out-of-state. What stands out as different in the reasoning of Obergefell is that members of the Court’s conservative wing invoked foreign law in a constitutional case about a domestic matter. By doing so, the Court’s conservatives appeared to contradict their own previous statements about the role of foreign law in interpreting the U.S. Constitution. Besides legalizing marriage equality, Obergefell may therefore also set an important precedent as to the appropriateness of citing foreign sources in constitutional decisions.Download the article from SSRN at the link.