Case Law: Lawmakers Don't Make All the Laws

Updated by David Goguen, J.D., University of San Francisco School of Law
Legislators and other elected officials draft and enact statutes, but when it comes to lawsuits, another type of "law" may carry more weight.

It's often said that the U.S. is a nation of laws. And indeed, laws are seemingly everywhere you look. There are federal statutes covering everything from income taxes to employment discrimination. Every state has passed its own set of laws pertaining to criminal behavior and punishment, commercial activity, public health, education, and hundreds of other legal areas that touch our everyday lives. Not to mention the thousands of counties, cities and other municipalities that have enacted their own local legislation.

With all of this legal authority existing (and at times, overlapping), it's no surprise that people disagree over what a statute means, or how (or to whom) it is supposed to be applied. Many times, people turn to the court system to sort it all out. This is where another kind of legal authority known as "case law" can come into play.

Different Sources of "Law"

Let's start out by getting an overview of the most common types of "law" at both the federal and state level:

  • Statutes are laws passed by legislative bodies, such as the U.S. Congress or state legislatures.
  • Regulations are rules passed by agencies or legislatures, usually dictating a particular function of government, specifying a governmental procedure, or explaining how a particular law is to be implemented.
  • Constitutions set out the rights and liberties of citizens, and the structure and duties of government, both at the federal and state levels.
  • Case Law.

What is "Case Law"?

Case law consists of decisions handed down by courts over the years, with those rulings serving as "precedent" for other courts in the same jurisdiction to follow.

But this kind of authority doesn't come from just any court. At both the federal and state level, courts of appeal sit higher than trial courts on the ladder of judicial authority, and the main job of these courts of appeal is to review decisions made at the trial court level, especially where interpretation of a statute or procedural rule is at issue.

At the federal level, the courts that issue decisions like this include:

  • the 13 federal circuit courts of appeal, which, among other duties, consider appeals of decisions issued by the federal district courts (which serve as the "trial courts" of the federal system), and
  • the U.S. Supreme Court, which is considered the highest appellate court in the land.
Decisions handed down by the U.S. Supreme Court and the 13 federal circuit courts are published in case reporters, and are often referred to and cited by parties in federal cases.

The same appellate system is in place at the state level, where courts of appeal sit above trial-level courts, and a supreme court presides at the top of the judicial ladder in all 50 states.

In the United States, case law is sometimes called "common law," but it's not entirely accurate to use the two terms interchangeably. That's because "common law" can also refer to laws that originated in the United Kingdom and were passed down to or accepted by the 13 Colonies, and in some instances became the basis for laws adopted by new governments in the U.S.

"Stare Decisis" and "Binding" Precedent

Under a legal concept with a Latin name, "stare decisis," (meaning "stand by things decided") courts follow or at least consider other courts' decisions on particular matters. Usually, this involves lower courts making decisions that are consistent with decisions of higher courts in the same jurisdiction or area. In this situation, the higher court's decision is considered "binding."

Let's look at an example. State A passes a law banning the legal recognition of same-sex marriage. Citizens 1 and 2, same-sex partners, are denied a marriage license by State A, and they file a lawsuit in federal district court claiming the law violates their federal constitutional rights. The district court judge agrees with the Citizens, and the decision is later held up on appeal, with the federal circuit court affirming that the law is unconstitutional.

So, the federal circuit court's decision effectively strikes down the law, and any lower court in the circuit court's jurisdiction would need to abide by that decision.

The U.S. Supreme Court Has the Last Word

The U.S. Supreme Court is the "highest court in the land," and its decisions carry the most authority when it comes to "case law." So, in 2015, when the U.S. Supreme Court decided that state bans on same-sex marriage violate the Fourteenth Amendment to the U.S. Constitution, not only were those particular bans invalidated (in Kentucky, Michigan, Ohio, and Tennessee) but the decision (Obergefell v. Hodges) effectively legalized same-sex marriage across the nation.

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