Which US Supreme Court case established the Court's authority as the final interpreter of the US Constitution?

The decision in the Marbury v. Madison, 5 US 137 (1803) case established the doctrine of "judicial review," which is the Supreme Court's power to evaluate laws and declare them unconstitutional.

Chief Justice John Marshall reasoned that the language in Article III of the Constitution, which explicated and enumerated the power of the US Supreme Court, intended the Judicial branch (which the Supreme Court heads) to ensure all laws conform to constitutional mandates.

"The judicial power shall extend to all cases, in law and equity, arising under this Constitution, the laws of the United States, and treaties made, or which shall be made, under their authority..." [emphasis mine]

This clause can be interpreted to mean the Judicial branch is further empowered with the authority to determine whether legislation is constitutionally sound. If the Legislative or Executive branches are allowed to act unilaterally, without any form of oversight, then there is no means of protecting the integrity of the Constitution. This responsibility would logically fall to those with an understanding of law, the judiciary, or more specifically, the Supreme Court.

The Constitution limits the action of all branches of government, not just the judiciary. The lack of specific instruction for which cases fall under the Court's appellate jurisdiction, as opposed to the specificity of which cases are under its original jurisdiction, tends to suggest the Founding Fathers intended to provide the Court an expanded scope of responsibility with regard to safeguarding the Constitution, not a more limited one.

This is part of the system of checks and balances that helps ensure no single branch of the government becomes too powerful or tyrannical.

Case Citation:

Marbury v. Madison, 5 US 137 (1803)

For more information, see Related Questions, below.