Constitutional Law: Definition and Function

US Constitution
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Constitutional law is a body of law based on a ratified constitution or similar formative charter dealing with the fundamental principles by which a government exercises its authority. These principles typically define the roles and powers of the various branches of the government and the basic rights of the people.

Key Takeaways: Constitutional Law

  • Constitutional law is an area of law dealing with the interpretation and application of the powers, rights, and freedoms established by a formally adopted constitution or charter. It encompasses the powers of the various branches of government and the rights of the people.
  • Constitutional law evolves over time as it is interpreted by the courts and legislative bodies.
  • The protection of human rights and civil liberties are common elements of constitutional law.

Constitutional Law Definition

By establishing the authority of the government, as well as the rights of the people, constitutional law is the foundation of all other procedural and substantive laws applied within the country.

In most countries, constitutional law is derived from a written document, like the U.S. Constitution, adopted as an integral part of the country’s founding. While each of the country’s political subdivisions, such as states and provinces, may have its own constitution, the term “constitutional law” generally refers to the laws of the central government. In most federal governments, like the United States and Canada, constitutional law defines the relationship and division of powers between the central government and the state, provincial, or territorial governments. In most cases, constitutional law evolves over time it is modified by the government’s legislative or parliamentary branch and interpreted by its judicial branch.

Common elements of constitutional law include the provision and assurance of human rights and civil liberties, legislative powers, the division of governmental powers, and assurance of protection under the rule of law.

Civil Liberties and Human Rights

As essential elements of constitutional law, human rights and civil liberties protect the rights and freedoms of individuals against the actions of the government. Human rights refer to the natural rights and freedoms of all people no matter where they live, such as freedom from religious persecution or enslavement. Civil liberties are the rights and freedoms specifically granted to individuals by a constitution, such as the right to trial by jury or protection from unreasonable search and seizure by the police. 

Legislative Procedures

Constitutional law establishes rules and procedures by which governments legislate, or make laws. For example, the process for enacting new laws or amending existing laws, the method of amending the constitution, and the number of terms or years a member of the legislative body may serve. 

Separation of Powers

In most modern nations, constitutional law divides the power of the central government among three functional branches. These branches are typically an executive branch, a legislative branch, and a judicial branch. Most constitutions divide the governmental powers in a way to ensure that no one branch can dominate the other two. 

Rule of Law

The constitutions of virtually all nations establish a “rule of law,” the principle under which all persons, institutions, and entities within the country—including the government itself—are held equally accountable to the laws enacted by the central government. Constitutional law strives to ensure that these laws are: 

  • Created in public: The processes by which laws are made and enforced are clear, understandable, and open to the people.
  • Equally enforced: The laws themselves must be clearly stated, well publicized, stable, and evenly applied. 
  • Protective of basic rights: The laws must protect the fundamental rights of individuals, including civil liberties and human rights.
  • Independently administered: The laws must be interpreted and applied by judges who are impartial, politically neutral, and reflect the makeup of the communities they serve. 

Constitutional Law in the United States

As one of the best-recognized examples of constitutional law, the United States Constitution establishes three branches of the federal government, executive, legislative, and judicial, defines the federal government’s relationship with the states, and sets forth the rights of the people. 

The amendments to the Constitution, including those of the Bill of Rights, list the rights possessed specifically by the people. Rights not specifically listed in the Constitution are protected by the Tenth Amendment, which grants all rights not reserved to the federal government to the states or to the people. The Constitution also outlines and divides the powers of the three branches of government and creates a protective system of checks and balances of powers between the three branches.

The first article of the Constitution creates a framework of rules by which the legislative branch creates laws, which must be approved by the President of the United States as head of the executive branch before taking effect.

The U.S. Supreme Court resolves disputes involving constitutional issues. Since its landmark ruling in the 1803 case of Marbury v. Madison, the Supreme Court has, through the process of judicial review, acted as the ultimate interpreter of the Constitution. Decisions of the Supreme Court become a permanent part of constitutional law and are thus binding on the parties involved, as well as the federal and state governments and the people. 

Sources and Further Reference

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Longley, Robert. "Constitutional Law: Definition and Function." ThoughtCo, Dec. 6, 2021, Longley, Robert. (2021, December 6). Constitutional Law: Definition and Function. Retrieved from Longley, Robert. "Constitutional Law: Definition and Function." ThoughtCo. (accessed March 27, 2023).