Section 3

Constitutional Law

The rulebook for government: who has power, how it is divided, and where it stops.

The Constitution is the highest law in the country. Every other law, a city parking rule, a state statute, an act of Congress, has to fit inside it. Constitutional law is mostly about two questions: does the government have the power to do this, and does doing it violate someone's rights?

The Constitution and judicial review

The Constitution creates the three branches of government, lists their powers, and adds limits through the Bill of Rights and later amendments. But the document does not enforce itself. Courts do that through judicial review: the power to declare a law or government action unconstitutional and refuse to apply it.

Real-life example

A city passes an ordinance banning all leafleting on public sidewalks. A student handing out flyers about a tuition increase is ticketed. She can challenge the ordinance in court, and a judge can strike it down even though it was passed by elected officials.

Separation of powers and checks and balances

Power is split among three branches so that no single one controls everything:

Legislative (Congress): writes statutes, controls spending and taxes.
Executive (the President and agencies): enforces the law and runs the federal government.
Judicial (the courts): interprets the law and resolves disputes.

Each branch also checks the others. The President can veto a bill; Congress can override the veto, confirm or reject judges, and control funding; courts can hold actions of both branches unconstitutional.

Real-life example

Your federal student aid exists because Congress created and funded the program, the Department of Education writes the detailed regulations and runs it, and a court can review whether those regulations go beyond what Congress actually authorized.

Federalism: national power and state power

Federalism divides authority between the national government and the states. The federal government has the powers the Constitution lists, for example, regulating commerce among the states. States keep broad authority over everyday life: traffic laws, most crimes, contracts, family law, and school rules.

When a valid federal law and a state law truly conflict, the federal law wins under the Supremacy Clause. That is why some rules are the same nationwide and others change the moment you cross a state line.

Real-life example

The drinking age, the speed limit on your commute, and how old you must be to sign a binding lease are set by your state. Federal law governs things like immigration status and nationwide employment discrimination protections.

Due process and equal protection

Due process appears in the Fifth Amendment (limiting the federal government) and the Fourteenth Amendment (limiting the states). Procedural due process means fair procedures before the government takes your life, liberty, or property, usually notice of what you are accused of and a real chance to respond. Substantive due process protects certain fundamental liberties from government interference no matter how fair the procedure is.

Equal protection, also in the Fourteenth Amendment, requires government to treat similarly situated people alike. Courts review classifications at different levels of strictness: race and national origin get the most searching review, sex gets intermediate review, and most economic or general classifications only need a rational reason.

Real-life example

A public university suspends a student for cheating. Due process generally requires telling the student what the accusation is and giving a chance to give their side before the suspension becomes final.

Why This Matters

Constitutional law is not only about famous national cases. It decides whether your public college can punish you for a post, whether police need a warrant to look through your phone, and whether a state can treat you differently from someone else. Knowing that the government must both have power to act and respect your rights gives you a way to ask better questions when something feels unfair.

Did You Know?

The Constitution is one of the shortest national constitutions in the world and has been amended only 27 times since 1789, and the first ten of those amendments, the Bill of Rights, were ratified together in 1791.

Check your understanding: Constitutional Law

Score: 0 / 3

1. What is judicial review?
2. A President seizes private factories during a war without any statute authorizing it. Which principle is most directly at issue?
3. Your state sets the speed limit on a local road. This reflects:

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