Quote from AAAintheBeltway:
Public policy in the US, as articulated by our courts, is hostile to private governing arrangements. Citizens are guaranteed certain rights and a democratic system of government by the Constitution. Parties to a contract can specfically provide for alternative dispute resolution such as arbitration, but even that will not be recognized in all types of cases. What muslims want to do is carve out entire reservations that they can govern as they choose under the guise of sharia law. In effect, they want to set up an alternative govenrment. It is a way of forcing all muslims, even the liberal or moderate ones, under the rule of fundamentalist imans.