The institutional significance of Marbury is that it was the first time that the Supreme Court, in an opinion of the court, had asserted its power to determine whether the acts of another branch satisfied constitutional standards. More significantly, it was the first time the Court, speaking as a court, provided a rationale for that power.
Marshall’s opinion consisted of essentially five propositions, seeming to echo the argument Alexander Hamilton writing as Publius had made in Federalist No. 78:
Marshall’s opinion was a sweeping declaration of constitutional principles, particularly the conclusion that it is “the province and duty of the judicial department to say what the law is.” In 1910, constitutional scholar Edward Corwin used the term “judicial review” to describe the power that the Supreme Court exercises when it decides cases that require constitutional interpretation. That term has been used ever since.
In the extensive literature about Marbury, the decision is described variously as placing the Supreme Court on equal footing with the other two branches of government and as placing the Supreme Court above the other two branches. Debates persist about whether courts should have the power of judicial review. In a letter to Abigail Adams in 1804, President Thomas Jefferson explained his opposition to judicial review:
The Constitution . . . meant that its coordinate branches should be checks on each other. But the opinion which gives to the judges the right to decide what laws are constitutional and what not, not only for themselves in their own sphere of action but for the Legislature and Executive also in their spheres, would make the Judiciary a despotic branch.
Despite controversy about the power of judicial review, Marbury has never been overruled. Neither has a constitutional amendment been adopted giving Congress the power to override constitutional decisions by the Supreme Court or requiring the justices to decide constitutional cases by greater than a simple majority. Rather, the debate has shifted to whether federal courts in general and the Supreme Court in particular have interpreted the Constitution properly.