The most important power the Supreme Court exercises is not explicitly mentioned in the Constitution. Judicial review—the power to declare a law passed by Congress and signed by the president unconstitutional—was enshrined in constitutional doctrine by Chief Justice John Marshall largely through Marbury v. Madison.
The power that came to be known as “judicial review” refers to those court decisions that have the effect of invalidating legislation (whether passed by state or federal legislatures) on the basis that it violates the more fundamental law of the Constitution. British judges had occasionally struck down laws which they found inconsistent with the British constitution, but the practice is even more closely tied to the American choice to write their constitutions down. Written constitutions have the effect, in a sense, of elevating the role of the judiciary power. In regimes with unwritten constitutions, legislators are generally their own judges with regard to the propriety of the laws that they pass. Judges, consequently, had very limited discretion when judging the propriety of the laws themselves, and political theorists had generally regarded the judicial branch as rather inconsequential. Locke had not even included the judiciary power as one of the three branches of government. And Hamilton noted in Federalist No. 78: “The celebrated Montesquieu, speaking of [the three departments of power], says: ‘Of the three powers above mentioned, the JUDICIARY is next to nothing.’” Those prior observations about the weakness of judiciaries was about to undergo an alteration as a result of America’s Constitution. A written constitution, if it is to be honored, requires judges to decide whether ordinary legislation has been passed in accordance with the Supreme Law. Hence, judicial review follows by logical necessity from written constitutions. Not all Americans immediately accepted this consequence, either from state constitutions or the United States Constitution, but this principle has generally been adopted in the intervening years.
The Constitution nowhere specifies that the courts shall be endowed with this power, but it would be reasonable to say that this power was implied by the Constitution’s Supremacy Clause and was understood, and often presupposed, by the Framers, Ratifiers, and even the opponents of the Constitution. A couple of outliers at the Constitutional Convention, John Mercer and John Dickinson, “disapproved of the doctrine, that the judges, as expositors of the Constitution, should have authority to declare a law void” (Aug. 15). But the greater number of the Framers, including James Madison, simply assumed that the courts would have this power (see, for instance, Madison’s speech on July 17 and Mason’s speech on July 21). Hamilton in Federalist No. 78 explained that “a constitution is, in fact, and must be regarded by the judges as, a fundamental law.” Judges, therefore, “ought to regulate their decisions by the fundamental laws rather than by those which are not fundamental.”
During Virginia’s ratifying debates, future Chief Justice John Marshall was already propounding what he considered to be the ineluctable conclusion of having a written constitution: “If [Congress] were to make a law not warranted by any of the powers enumerated, it would be considered by the judges as an infringement of the Constitution which they are to guard. . . . They would declare it void.” He further asked, “to what quarter will you look for protection from an infringement on the Constitution, if you will not give the power to the judiciary?” (June 20, 1788). Even the Anti-Federalists assumed that the judges would have this power, and criticized the Constitution on these grounds. The power to declare an act of the legislature void, claimed “Brutus,” means that the judges’ “power is superior to that of the legislature” (Brutus No. 15, one author of the Anti-Federalist Papers).