Judicial Branch: Interpreting and Applying Laws

The Judicial Branch of the Federal Government

More than 600 judges sit on federal district courts, and nine justices make up the Supreme Court. Presidents nominate and Senate confirm judges, who serve for life.

The Constitution doesn’t specify how many justices there should be. Throughout history, Congress has changed the number, fluctuating between five and ten, before settling on nine with the Judiciary Act of 1869.

The Judicial Branch

The judicial branch of the federal government interprets and applies laws, acting as a check on the executive and legislative branches. It sets legal precedents that shape American society. Judges and justices are selected by the President and confirmed by the Senate, and they have lifetime appointments that cannot be reduced during their tenure.

The Constitution doesn’t go into much detail about the structure of the judiciary, leaving Congress to decide the number of Supreme Court Justices and how the rest of the federal courts should be organized. During the Civil War, Congress tried to shrink SCOTUS down to six judges so that a future President wouldn’t be able to add more, but the number was restored to nine in 1869.

The United States has a unique system of federal courts that includes district courts, 13 circuit courts of appeal, and the Supreme Court. The Supreme Court handles all appeals from lower courts and some cases of national significance.


There are more than 600 judges on district courts, almost 200 judges on appeals courts, and nine justices who make up the Supreme Court. When a vacancy occurs, the president nominates someone to the post. The nominee goes through a vetting process, which may include a hearing before the Senate Judiciary Committee. Presidents get recommendations from a number of sources, including the Department of Justice, sitting judges and justices, members of Congress, and interest groups.

The nine Justices hear cases that challenge the Constitution, interpret legislation, protect civil rights, and resolve disputes between states or between the federal government and private parties. In addition to legal briefs submitted by attorneys, the Justices typically listen to oral arguments in which each side has 30 minutes to present their case before the Justices ask questions. The Justices then meet in private to discuss the case and issue a decision. These decisions often shape policy as profoundly as any passed by Congress or enacted by the executive branch.


The Justices of the Supreme Court release their decisions along with detailed explanations of why they voted the way that they did. Justices whose point of view did not prevail may also write a separate dissenting opinion.

In some cases, Justices who agree with the result but reach different conclusions for their own reasons present a concurring opinion. This can happen when there is a tie vote or when a Justice recuses herself from a case and another Justice steps in to hear the case.

While Presidents are more likely to choose judges who share their political ideology, partisan bias is still prevalent in the Court. In fact, the majority of Justices are appointed by a president of their own party, and this makes for a biased Court. Changing the way Justices are selected would help reduce partisanship on the Supreme Court. One popular reform option is to impose term limits and regularize appointments. This would make it more difficult for any one president to dominate the Court for multiple terms.


The Supreme Court receives thousands of petitions for cases each year, but it only takes a small number of them. If four Justices feel a case is important enough to consider, they issue a writ of certiorari—a legal order asking lower courts to send the Court the case records.

The Justices review the papers, listen to arguments from the parties in the case, and then decide how to rule. They typically write a majority opinion explaining their decision, and the Justices who disagree release a dissenting opinion.

The justices also sometimes write separate concurring opinions—thoughtful addendums to the majority’s decision. Most Justices were lawyers before becoming judges, and many attended Harvard Law School. Once a Justice is elected, his or her tenure is for life—as long as they maintain good behavior and do not resign. Historically, no sitting Justice has ever been impeached.

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