Oklahoma voters on Tuesday approved State Question 755 [text, PDF], an amendment to the state constitution [text] that bans the use of Islamic or international law in state court decisions. The amendment, also known as the Save Our State amendment, was approved by voters 70 percent to 30 percent [unofficial results]. The amendment was overwhelmingly approved by the state legislature before Tuesday's vote and allows state courts only to look to legal precedents of other states for guidance, provided that state does not use Islamic law. The amendment also prevents courts from "look[ing] to the legal precepts of other nations or cultures."
The law was sponsored by state Representative Rex Duncan (R) [official website], who described it as a preemptive strike [Daily Mail report] against the use of Islamic law in Oklahoma. The necessity of the amendment has been questioned [CNN report], due to the fact that the use of Islamic law in US courts would likely violate the First Amendment [Cornell LII backgrounder] prohibition on laws respecting an establishment of religion in the US Constitution [text].