“According to Islamic law specialist Abed Awad, bans on sharia law are actually unconstitutional. Sharia law, like any foreign law or other religious law, is to be used as ‘parol evidence’ or ‘extrinsic evidence’ and provide cultural context for a ruling,” writes Rahel Gebreyes in The Huffington Post.

Why then are states passing laws to ban sharia?

See a discussion here: “The Unfortunate Consequences Of Banning Sharia Law”