Case law doesn’t exist in the United States of America. You might be thinking about medieval England, or ancient Persia, where a king or judge’s word becomes law. In the USA, people are judged individually and are equal before the law. One exception, that is traditional, but not enumerated in law, is that the Supreme Court can strike down a law that it deems unconstitutional, but may not amend or make new laws itself. Lower courts havee Ed no such power.