This involves federalism and a respect for states' autonomy. Article IV of the U.S. Constitution declares that federal constitution and federal laws are the supreme law of the land. This doctrine of national supremacy provides the basis for the U.S. Supreme Court's review of state court rulings.
Nonetheless, a fine balance must be maintained between national supremacy and the rights of states in a federal system. Therefore, the presumption is that the states are capable of rectifying their own errors and the federal judiciary should not step in too readily or easily.
