Here’s something that surprises a lot of people: nowhere in the Constitution does it say that courts can declare laws unconstitutional and strike them down. Not in Article III. Not in the Bill of Rights. Nowhere.
And yet, courts do this all the time. It’s called judicial review, and it’s one of the most powerful tools in the American system of checks and balances. So how did courts get this authority? And more importantly — how does it actually work when a court decides to overturn a law?
The Case That Changed Everything
Judicial review as we know it started with a Supreme Court case in 1803 called Marbury v. Madison. The details of the case itself are pretty wonky — it involved whether a guy named William Marbury had a right to a commission as a justice of the peace that President John Adams appointed him to in the final hours of his administration.
But Chief Justice John Marshall used the case to establish something much bigger. He wrote that if a law conflicts with the Constitution, the Constitution wins. And since it’s the job of courts to interpret laws, it’s also their job to decide when a law violates the Constitution — and to refuse to enforce that law.
Marshall’s logic went like this: judges take an oath to uphold the Constitution. If Congress passes a law that contradicts the Constitution, which one should judges follow? The Constitution is the supreme law of the land, so it has to take priority. Therefore, courts must have the power to declare unconstitutional laws invalid.
It was elegant reasoning, and it stuck. No amendment was needed. No vote in Congress. Just one court opinion that gave the judicial branch a way to check the other two branches.
How Courts Actually Review Laws
So what happens when someone thinks a law is unconstitutional? They can’t just call up the Supreme Court and complain. Judicial review only happens through actual court cases — meaning there has to be a real dispute between parties with something at stake.
Here’s the typical path: Someone gets charged with violating a law, or they’re harmed by a law and want to challenge it. They file a lawsuit in a trial court (federal or state, depending on the law). Their lawyer argues that the law itself violates the Constitution — maybe it restricts free speech, or treats people unequally, or oversteps what the government is allowed to do.
The judge examines the law against the relevant part of the Constitution. Different types of laws get different levels of scrutiny. If a law involves fundamental rights or treats people differently based on race, courts apply “strict scrutiny” — the government has to prove it has a compelling reason for the law and that it’s narrowly tailored to achieve that goal. That’s a high bar. Other laws get more relaxed review.
If the trial court strikes down the law, the government can appeal. If the trial court upholds it, the person challenging the law can appeal. Cases can work their way up through appeals courts, and sometimes — though rarely — all the way to the Supreme Court.
It’s Not Just the Supreme Court
When people think about judicial review, they usually picture the Supreme Court making sweeping pronouncements. And yes, when the Supreme Court declares a federal law unconstitutional, that’s the final word.
But federal district courts and appeals courts exercise judicial review too. So do state courts — they can strike down state laws that violate either the state constitution or the U.S. Constitution. Most judicial review actually happens at these lower levels, often without much fanfare.
The difference is that lower court decisions only bind the parties in that case or, for appeals courts, the courts within their circuit. A district court in Texas striking down a federal regulation doesn’t automatically invalidate that regulation nationwide — though the practical effects can still be significant. Only the Supreme Court can make a binding decision that applies across the entire country.
What Happens When a Law Gets Struck Down
When a court declares a law unconstitutional, that law becomes unenforceable — at least within that court’s jurisdiction. State and federal officials can’t enforce it. Prosecutors can’t charge people under it. Government agencies can’t implement it.
But here’s where it gets interesting: Congress or state legislatures can respond by rewriting the law to fix the constitutional problem. Courts don’t have the power to write laws themselves — they can only say “this particular law, as written, violates the Constitution.”
Sometimes the fix is simple. If a court strikes down a law because it’s too vague, the legislature can rewrite it with clearer language. If the problem is that the law sweeps too broadly, they can narrow it. Other times, the constitutional problem is fundamental and there’s no way to rewrite the law to save it.
And technically, Congress or a state legislature could even pass the exact same law again. The court would likely strike it down again, but there’s no formal mechanism stopping the legislature from trying. This rarely happens because it’s usually a waste of time — but it illustrates that courts and legislatures operate in an ongoing conversation, not a simple hierarchy.
The Limits of Judicial Power
Judicial review is powerful, but it comes with built-in constraints.
First, courts can only rule on cases that are properly before them. They need a plaintiff with “standing” — meaning someone who’s been actually harmed and can show a concrete injury, not just a general grievance. Courts can’t issue advisory opinions about whether a hypothetical law would be constitutional.
Second, courts generally try to avoid constitutional questions if they can resolve a case on narrower grounds. This is called “constitutional avoidance” — if a court can interpret a law in a way that makes it constitutional, they’ll usually do that instead of striking it down.
Third, courts have historically shown some deference to the elected branches on certain issues. They’re more reluctant to second-guess Congress or state legislatures on economic regulations or matters of foreign policy than on individual rights. The level of deference has shifted over time, but the basic principle remains.
And finally — and this is important — courts have no power to enforce their own decisions. They depend on the executive branch to actually implement their rulings. As Andrew Jackson supposedly said about a Supreme Court decision he disagreed with: “John Marshall has made his decision; now let him enforce it.” Courts have moral authority and legal authority, but not police forces.
Why It Matters for Regular People
Judicial review might sound like an abstract legal concept, but it’s the mechanism that has struck down school segregation laws, protected freedom of speech, limited government surveillance, and resolved countless other issues that directly affect people’s lives.
Every time you hear about a court blocking a law or regulation, that’s judicial review in action. Understanding how it works — including its limits — helps make sense of why some legal battles take years, why rulings sometimes seem narrow or technical, and why the composition of courts matters so much.
The system was designed so that no single branch could have unchecked power. Judicial review is how courts hold up their end of that bargain.