=Power of the Supreme Court to Declare Laws Unconstitutional.=--An important power of the Supreme Court for which there is no direct authority in the Constitution, is that of declaring acts of Congress which are in conflict with the Constitution, null and void and of no effect. This power was first exercised by the Supreme Court in 1801 in the famous case of Marbury v. Madison. Congress had passed an act giving the Supreme Court original jurisdiction in certain cases where the Constitution says it should have appellate jurisdiction, and when the act came before the court for enforcement it declined to be bound by it. The great chief justice, John Marshall, wrote the opinion of the court which held the act of Congress null and void. His argument, in brief, was that the Constitution is the supreme law of the land and the judges are bound to give effect to it. When, therefore, the court is called upon to give effect to a law of Congress which is clearly in conflict with the higher law of the Constitution, it must give the preference to the latter, otherwise the declaration in favor of the supremacy of the Constitution would have no meaning. Down to 1913 the Supreme Court had declared thirty-three acts of Congress, or parts of such acts, unconstitutional. _Power to Declare State Laws Unconstitutional._--Laws passed by the state legislatures, ordinances of municipal councils, and even the provisions of state constitutions themselves may be declared null and void by the Supreme Court in case they are in conflict with the national Constitution or the laws and treaties made in pursuance thereof. It has already been pointed out that appeals may be taken to the federal Supreme Court from the highest courts of a state whenever a right, title, or privilege under the federal Constitution is involved and the state court has decided against the right or privilege claimed. Thus where one is prosecuted and convicted under a state law or provision of a state Constitution which he claims is contrary to some provision in the federal Constitution or laws, he has a right to appeal to the United States Supreme Court and have the question of the constitutionality of the state law finally determined there. This is a necessary consequence of the supremacy of the federal Constitution and laws over those of the states. More than 200 acts of state legislatures have been pronounced null and void by the United States Supreme Court.[102] [102] Baldwin, "The American Judiciary," p. 106. Sometimes inferior federal courts declare acts of Congress and of the state legislatures to be unconstitutional, but in all such cases an appeal may be taken to the Supreme Court for final review.