This doesn't ban Islam. It bans the use of Sharia in court, which could be used to harm non-Muslims and women, which would violate the US Constitution's currently guaranteed equal protection.
But even if it were an amendment to the US Constitution, somehow a liberal judge would find a way to throw it out as unconstitutional. If you're putting it in the Constitution, that would mean it's unconstitutional right now, so the act of trying to put it into the Constitution is unconstitutional. Nice catch-22.
Cut off the judges hands for stealing freedom