Nine judges appointed for life have the final say on America’s toughest legal questions. Here’s how the U.S. Supreme Court works, and why its decisions reach far beyond the U.S.
The U.S. Supreme Court is the final court of appeal in the American legal system. Its rulings apply across the country, and can only be overturned by a later Supreme Court decision or a change to the Constitution.
Its most important power is judicial review: the ability to strike down laws or government actions that it decides breach the U.S. Constitution. That power isn’t written in the Constitution itself, but the court claimed it in a famous 1803 case, Marbury v. Madison, and it has been accepted ever since.
There are nine justices: a Chief Justice, currently John Roberts, and eight associate justices. They are nominated by the president and must be confirmed by a majority vote in the Senate. Once appointed, they serve for life, unless they retire, die or are impeached and removed.
Because a single appointment can shape the court for decades, nominations are among the most fiercely contested fights in U.S. politics. Donald Trump appointed three justices in his first term: Neil Gorsuch, Brett Kavanaugh and Amy Coney Barrett.
How it decides cases
The court chooses which cases it hears. Each year, it receives thousands of requests and agrees to hear only around 60. Its term begins on the first Monday in October, and its biggest decisions usually come in June.
Cases are decided by majority vote. The court’s six justices appointed by Republican presidents are generally seen as conservative, and its three appointed by Democratic presidents as liberal, although votes don’t always split that way.
Its rulings have changed American life. In 2022, it overturned Roe v. Wade, ending the national constitutional right to abortion. In 2024, it ruled that presidents have broad immunity from criminal prosecution for official acts.
The court has also checked presidential power. In February 2026, it ruled 6–3 that Trump couldn’t use an emergency economic powers law to impose sweeping tariffs, a decision with major consequences for global trade.
Speculation about retirements is a constant feature of Washington. Justices often time their departure so a president from the party that appointed them can choose their replacement, which is why the Senate result in the midterms is watched closely.
Critics argue lifetime appointments give too much power to unelected judges, and some have proposed term limits or expanding the court. Supporters say lifetime tenure protects judges from political pressure.
