A more thorough explanation:

Constitutional law is the study of the interpretation and application of the United States Constitution. The Constitution is the source of legal authority for the United States, and questions of constitutional law often relate to fundamental questions of sovereignty and democracy. The Supreme Court has the power of judicial review, which allows them to declare actions of governmental bodies unconstitutional and prevent them from being enforced.

The Constitution follows a system of enumerated powers and separation of powers between three branches of the federal government: executive, legislative, and judicial. These three branches are designed to check and balance any potential overreach of power by the other branches. The text of the Constitution is split between 7 Articles and a collection of underlying sections.

For example, the First Amendment protects the freedom of speech, religion, and the press. The Second Amendment protects the right to bear arms. The Fourth Amendment protects against unreasonable searches and seizures. The Fourteenth Amendment prohibits the states from abridging "the rights and immunities" of any citizen without due process of law, as well as guarantees equal protection of the law for all citizens.

The Constitution has been amended 27 times since it was first passed. The first ten amendments, called the Bill of Rights, were ratified in 1791 and provide a check on the federal government. The Thirteenth Amendment made chattel slavery illegal. The Nineteenth Amendment guarantees the right to vote regardless of sex. The Twenty-Sixth Amendment extends the right to vote to 18 year olds.

Overall, constitutional law is a complex and important field that helps to ensure that the United States government operates within the bounds of the Constitution and protects the rights of its citizens.