In the years preceding the U.S. Supreme Court's ruling in Marbury v. Madison (1803), Americans gradually came to accept the notion that courts could in certain instances strike down laws as contrary to a constitution. They formulated a rationale for judicial review (a term coined in the twentieth century) that drew upon several interrelated ideas, including fundamental law, written constitutions, popular sovereignty, and the separation of powers. Eighteenth-century Americans firmly believed that the acts adopted by their legislatures should conform to some unwritten "higher" or "fundamental law," variously referred to as divine or natural law; the immutable standards of reason, morality, and justice; or the principles embodied in the British constitution. Unwritten fundamental law was not the kind of law that judges were particularly qualified to enforce, however, because it was too general and amorphous to accommodate itself to judicial interpretation. After 1776, however, Americans began to identify fundamental law with the written constitutions that accompanied the establishment of their new state governments. These constitutions provided the concreteness and specificity of written documents that were the staple ofjudicial exposition. In time, written American constitutions, including the U.S. Constitution, came to be framed and adopted by conventions elected for the purpose. A constitution so formed was perceived to be more than a plan of government but a "law" enacted by the supreme legislative power, the sovereign people. It was a law of superior obligation, imposing limits upon government that were to be obeyed in the same way citizens obeyed ordinary laws.
The concept of supreme law as the original and deliberate act of the people was the indispensable basis for a theory of judicial review compatible with popular government. In the emerging American doctrine of separation of powers, legislature, executive, and judiciary were joined together in an equality of subordination to the people. The judiciary, in consequence, could plausibly claim that to uphold a constitution was to preserve and enforce the people's permanent will. To void an act as contrary to a constitution was not an encroachment upon legislative power but a legitimate exercise of the judiciary's province to declare the law.
Before 1803 state and federal courts explicitly or implicitly endorsed the doctrine of judicial review; for example, Bayard v. Singleton (1787), a North Carolina case, and Hylton v. U.S. (1796), in the U.S. Supreme Court. The most articulate defense, however, was undertaken by Alexander Hamilton. Writing as Publius in The Federalist No. 78 (1788), Hamilton set forth the essential elements of the doctrine: the Constitution was a written fundamental law enacted by the people; courts were the peculiar guardians of the Constitution, trustees acting on behalf of the people; the refusal to uphold a law contrary to the Constitution did not imply judicial superiority over the legislative power but "only supposes that the power of the people is superior to both"; and choosing between Constitution and statute was an act of discretion wholly within the scope of judicial power, no different in kind from that exercised in ordinary cases of determining between two contradictory laws. This argument was effective in persuading Americans that judicial review was both a sound theory and a practical means of insuring that popular government would also be orderly and constitutional government.