The US Supreme Court has started debating a law that could ultimately gut the historic Roe v Wade ruling. The 1973 case affirmed abortion rights in the US. The Justices are considering whether legislation in the state of Mississippi, which limits terminations to 15 weeks after pregnancy, is constitutional. If they uphold the Mississippi law, many other states will likely introduce far more restrictive abortion rules. From Washington, our North America Correspondent Jon Brain reports.