What Is Constitutional Law: Principles, Rights, and Judicial Review

What Is Constitutional Law?

Constitutional law is the body of law that derives from a nation's constitution—the foundational legal document that establishes the structure of government, defines the powers and limitations of governmental branches, and guarantees individual rights and liberties. In the United States, constitutional law is centered on the interpretation and application of the U.S. Constitution, ratified in 1788, along with its 27 amendments.

Constitutional law governs the relationship between government and individuals and among the branches of government themselves. It answers fundamental questions: What can Congress legislate? What powers does the President hold? When can the government restrict individual liberty? What rights are so fundamental that no government may infringe upon them?

The Structure of the U.S. Constitution

The U.S. Constitution consists of a Preamble, seven original Articles, and 27 amendments. The original seven Articles divide governmental power:

• Article I: Establishes the legislative branch (Congress)—the Senate and House of Representatives—and enumerates its powers, including taxation, commerce regulation, and declaring war.
• Article II: Establishes the executive branch (the President) with powers including commanding the military, making treaties, and appointing federal officers.
• Article III: Establishes the judicial branch (the federal courts, including the Supreme Court) and grants jurisdiction over federal questions and disputes between states.
• Articles IV–VII: Address relations between states, the amendment process, the supremacy of federal law (Supremacy Clause), and ratification.

Separation of Powers and Checks and Balances

A core principle of U.S. constitutional structure is the separation of powers among three branches—legislative, executive, and judicial—each with distinct roles. Complementing this is the system of checks and balances, giving each branch mechanisms to limit the others:

• Congress makes laws; the President can veto them; Congress can override a veto by a two-thirds supermajority in both chambers.
• The President appoints federal judges; the Senate must confirm them.
• Courts can invalidate laws passed by Congress or actions taken by the executive as unconstitutional.

The Bill of Rights and Individual Liberties

The first ten amendments to the Constitution, ratified in 1791 as the Bill of Rights, protect individual liberties from government infringement. Key amendments include:

The Fourteenth Amendment and Incorporation

Ratified in 1868 after the Civil War, the Fourteenth Amendment is among the most consequential in U.S. constitutional history. Its key clauses include:

• Equal Protection Clause: No state may deny any person within its jurisdiction the equal protection of the laws. This clause has been the basis for major civil rights decisions, including those invalidating racial segregation and sex discrimination.
• Due Process Clause: No state may deprive any person of life, liberty, or property without due process of law. The Supreme Court has interpreted this clause to incorporate most of the Bill of Rights against the states through the "selective incorporation" doctrine.
• Privileges or Immunities Clause: Protects the privileges and immunities of U.S. citizenship from state infringement (though its scope has been interpreted narrowly).

Through incorporation, most Bill of Rights protections—originally applicable only to the federal government—now apply to state and local governments as well.

Judicial Review

Judicial review—the power of federal courts to declare acts of Congress or the executive unconstitutional—is not explicitly stated in the Constitution but was firmly established by the Supreme Court in Marbury v. Madison (1803). Chief Justice John Marshall's opinion established that it is "emphatically the province and duty of the Judicial Department to say what the law is."

Judicial review allows courts to strike down legislation that violates constitutional provisions. The standard of review applied by courts varies based on the right or classification involved:

Landmark Supreme Court Cases

• Marbury v. Madison (1803): Established judicial review.
• McCulloch v. Maryland (1819): Affirmed the implied powers of Congress under the Necessary and Proper Clause.
• Brown v. Board of Education (1954): Overturned Plessy v. Ferguson (1896) and held that racial segregation in public schools violates the Equal Protection Clause.
• Gideon v. Wainwright (1963): Held that the Sixth Amendment right to counsel applies to state criminal proceedings through the Fourteenth Amendment.
• Miranda v. Arizona (1966): Required law enforcement to inform suspects of their constitutional rights before custodial interrogation.
• Roe v. Wade (1973): Recognized a constitutional right to abortion under the due process right to privacy; overturned by Dobbs v. Jackson Women's Health Organization (2022).
• United States v. Nixon (1974): Held that executive privilege is not absolute and does not shield the President from judicial demands for evidence in criminal proceedings.
• Citizens United v. FEC (2010): Held that the First Amendment prohibits government restrictions on corporate political spending.

Constitutional Interpretation: Originalism vs. Living Constitutionalism

Constitutional scholars and jurists debate how to interpret constitutional provisions. Originalists argue that the Constitution should be interpreted based on its original public meaning at the time of ratification. Living constitutionalists argue that the Constitution's broad principles should be interpreted in light of contemporary values and societal changes. This debate shapes judicial appointments, Supreme Court decisions, and the trajectory of constitutional law over time.

This article is for informational purposes only and does not constitute legal advice. Consult a qualified attorney before taking any legal action.