The very idea of Shari’a courts and law would be as unconstitutional as something could possibly be in this country. This is exactly what the founders meant when they wrote their very first amendment, “Congress shall make no law respecting an establishment of religion”. Unfortunately the same words prevent Congress from acting against Shari’a law. The bottom line is that, when you’re in the USA, you are subject to USA law and no other. Whatever you do in your church or your mosque or your pile of sacred timber is your business, but if you kill someone or otherwise break USA law, your religion does not protect you.
“Whatever you do in your church or your mosque or your pile of sacred timber is your business, but if you kill someone or otherwise break USA law, your religion does not protect you.”
Generally yes, but the so-called cultural defense is making inroads even here. This is where the court will take into account cultural, including religious beliefs, in determining whether your crime meets all the elements for conviction. It has been raised in issues as diverse as honor killings and drowning your own kids, in murdering a rival or kidnapping a child from the custodial parent.