Final answer:
The Marbury v. Madison case established the principle of judicial review, greatly strengthening the role of the U.S. Supreme Court by affirming its power to declare legislative and executive actions unconstitutional.
Step-by-step explanation:
The case of Marbury v. Madison had a profound impact on the U.S. Supreme Court. Chief Justice John Marshall's ruling established the principle of judicial review, which affirmed the Court's authority to override congressional and presidential actions it found unconstitutional. While the case emerged from a dispute between the outgoing administration of President Adams and incoming President Jefferson, it became a defining moment for the Supreme Court. Although William Marbury never received his commission and the court avoided a direct political confrontation, it secured a significant expansion of judicial power.
By declaring a section of the Judiciary Act of 1789 unconstitutional, the court confirmed its role as a guardian of the Constitution and positioned itself as a central fixture in government, responsible for guiding national policy. This decision enforced the notion that the judicial branch is a strong check on the other branches of government. Consequently, the ruling entrenched the Court's role in the balance of power, setting a precedent followed to this day.