The Oklahoma chapter of the Council on American-Islamic Relations (CAIR) [advocacy websites] filed a lawsuit [text, PDF; press release] Thursday challenging the constitutionality of State Question 755 [text], which amends the state constitution [text] to ban the use of Islamic or international law in state court decisions. The suit, filed in the US District Court for the Western District of Oklahoma [official website], seeks to block the Oklahoma State Board of Elections [official website] from certifying this week's election results, which approved the measure [JURIST report] by a vote of 70 to 30 percent [unofficial results]. CAIR argues that the law violates the Establishment Clause [Cornell LII backgrounder] of the First Amendment. The law would prevent Oklahoma courts from "look[ing] to the legal precepts of other nations or cultures," requiring them only to look to legal precedents of other states for guidance, provided that state does not use Islamic law.
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 prohibition on laws respecting an establishment of religion.