We shouldn't ban Sharia law

You may have heard that an Oklahoma court enjoined the newly enacted state ban on the use of Sharia (and international law) in court.  The opinion is now available.  Here are the plaintiff's claims

[P]laintiff asserts that the moment Oklahoma’s constitution is amended, his First Amendment rights will be violated: (1) by Oklahoma’s official condemnation of his religion/faith as reflected through the amendment to Oklahoma’s constitution banning state courts’ use or consideration of Sharia Law, (2) by the invalidation of his last will and testament which incorporates various teachings of Mohammed, and (3) by the excessive entanglement of the state courts with religion that would result from the amendment as the state courts in implementing the amendment would have to determine what is and is not encompassed in Sharia Law.

I'm not entirely persuaded that a ban on Sharia law violates the First Amendment, but I do think that a categorical ban is unnecessary and unhelpful, especially if we care about the sort of robust pluralism spoken of by folks such as the Archbishop of Canterbury, who explored the question of "living under more than one jurisdiction."  My concern is foreclosing the possibility that Sharia law can shape the private ordering of Muslim citizens; I of course would oppose using Sharia law to define the public order.  If the law lacks the space to recognize that some of our commitments are not easily translated into a unitary legal regime, I think that Christians have cause to worry as well.