The Supreme Court is not always ruling on the Constitution. When they rule on a matter of statutory interpretation, the bits of federal common law that still e

The Supreme Court is not always ruling on the Constitution. When they rule on a matter of statutory interpretation, the bits of federal common law that still exist today, or other federal grounds for a decision that aren't about the Constitution, an Act of Congress is plenty sufficient to change that by eliminating or modifying the basis for the decision.