In CA they didn't change the law. They undid a tyrannical act by the CA Supreme Court in a 4-3 decision. They undid a law that was made up out of thin air.
My own view of rights aside the view of the US Supreme Court is that fundamental rights are "deeply rooted in this Nation's history and tradition." There is no way that gay marriage can possibly fall within this definition.
If LGBT folks want same-sex marriage legalized they need to do it with the consent of the people.