The Supreme Court decides a small number of immigration cases each year, but those decisions reshape the system for everyone. In 2025 and 2026 alone, the Court limited Nationwide injunctionA court order that blocks enforcement of a rule or policy for everyone, not only the parties to the case. In Trump v. CASA, decided June 27, 2025, the Supreme Court held that the Judiciary Act of 1789 does not authorize federal courts to issue injunctions broader than needed to give the parties complete relief, while leaving other paths to wider relief open.See it in the glossary and struck down the birthright citizenship Executive orderA directive from the President to federal agencies and officials about how to run the executive branch and carry out the law. Executive orders are numbered and published in the Federal Register, and they generally bind the executive branch.See it in the glossary. When news breaks that the Court has “taken” a case, it helps to know which of two very different tracks the case is on, and what happens next.
How a case reaches the Court
Most cases start in a federal district court or, for removal cases, in immigration court and the Board of Immigration Appeals (BIA)The administrative body within the Department of Justice that hears appeals from immigration judges and certain USCIS decisions.See it in the glossary. The losing side usually appeals to one of the federal courts of appeals. From there, the losing party can file a petition for a writ of CertiorariA request, called a petition for a writ of certiorari, asking the Supreme Court to review a lower court decision. The Court does not have to take the case and typically does so when it involves an unusually important legal principle or when federal appeals courts have read a law differently. In civil cases the petition generally must be filed within 90 days after judgment.See it in the glossary, asking the Supreme Court to review the decision.
The Court grants review only when at least four of the nine justices vote to hear the case. It takes a small fraction of petitions, and it tends to choose cases where appeals courts disagree with each other, where a federal law has been struck down, or where the national stakes are high. The government, through the Solicitor General, has a stronger track record of getting its petitions granted than private parties do.
In some cases, a party asks the Court to take a case before the court of appeals rules. This is called certiorari before judgment. The birthright citizenship case followed that path: the government asked the justices on September 26, 2025 to review a New Hampshire injunction without waiting for the First Circuit, and the Court agreed on December 5, according to SCOTUSblog.
Track 1: The merits docket
When the Court grants certiorari, the case goes on its “merits docket.” That means full written briefs from the parties, often dozens of friend-of-the-court briefs, an oral argument, and a signed opinion explaining the result.
- Timing: the Court’s term begins on the first Monday in October. Cases granted by around January are usually argued that term and decided by the end of June or early July.
- Example: Trump v. Barbara was argued April 1, 2026 and decided June 30, 2026, when the Court held 6 to 3 that the executive order on birthright citizenship violated the Fourteenth Amendment, as the National Constitution Center reported.
Track 2: The emergency docket
Parties can also ask the Court for emergency relief, such as a stay of a lower court order while an appeal continues. These applications go first to the justice assigned to that circuit, who can decide alone or refer it to the full Court. The Court often rules in days or weeks, sometimes with a brief order and no full explanation.
Emergency orders are temporary, but they can decide what happens for months or years. Trump v. CASA began as an emergency application about birthright citizenship injunctions. The Court heard argument and, on June 27, 2025, held that federal courts generally lack authority to issue universal injunctions, without deciding whether the underlying executive order was lawful. That question came back on the merits docket a year later.
What happens to people while a case is pending
Granting review does not change the law by itself. The lower court’s ruling stays in place unless the Court issues a stay. That can mean:
- a policy remains blocked while the justices consider it; or
- a policy takes effect because the Court paused a lower court’s block.
For affected people, the practical question is always which order is currently in effect, not which way the Court might rule.
What a decision changes
It binds every court
A Supreme Court ruling on federal law is binding on all lower federal courts and on state courts. That is why a single decision can settle a question nationwide even after CASA limited universal injunctions.
It may not end the case
The Court often sends a case back to lower courts to apply its ruling. Remaining issues can take more months.
It may not end the policy debate
The government can respond by using a different tool, and Congress can amend a statute that the Court interpreted. After Trump v. Barbara, the President signed new executive orders on August 6, 2026 aimed at birthright citizenship, which challengers are contesting, according to the Asian Law Caucus. A constitutional ruling, however, can be changed only by a later Supreme Court decision or a constitutional amendment.
Immigration cases on the horizon
The government asked the Supreme Court to review a Georgetown scholar’s immigration detention case, which we covered in our report on the petition. Whether the Court takes it depends on the vote of four justices. Any immigration case the Court grants in the fall is usually argued in the winter or spring and decided by summer.
How to follow a case
- Check the Supreme Court’s docket for the case number, filings and orders.
- Note the date of argument, which signals when a decision is likely.
- After a decision, look for agency guidance on how it will comply. That is usually what changes filing practice.
Why it matters
A Supreme Court immigration decision can protect or narrow rights for millions of people at once, and it often defines how far the President and agencies can go. For how lower courts get to the same questions first, see why federal courts keep blocking immigration rules, and for the vocabulary, our legal terms glossary.
Common questions
Can the Supreme Court decide not to decide?
Yes. It can deny review, which leaves the lower court ruling in place without endorsing it, or dismiss a case after granting it. A denial of review is not a ruling on the merits.
How many justices must agree for a decision?
A majority of the justices participating, usually five of nine. Justices can write separate concurrences and dissents.
Do emergency orders set precedent?
Emergency orders are temporary and often unexplained, and lower courts treat their weight cautiously. Signed merits opinions are binding precedent.
Can Congress change a Supreme Court ruling?
If the ruling interprets a statute, Congress can amend the statute. If the ruling interprets the Constitution, as in the birthright citizenship case, only a later Supreme Court decision or a constitutional amendment can change it.