The highest federal court chooses a small number of cases, and the reasoning behind a decision often matters more than the outcome.
The Supreme Court hears arguments and issues written decisions that shape how the Constitution and federal law apply nationwide — but it controls its own docket almost entirely, choosing only a small fraction of the cases it’s asked to review each year.
It is emphatically the province and duty of the judicial department to say what the law is.
Chief Justice John Marshall, Marbury v. Madison (1803)
How a Case Actually Reaches the Court
The record starts well before the Supreme Court
Facts and legal arguments are developed in trial and appellate courts first. A losing party then petitions the Supreme Court to review the lower court’s decision — most petitions never get that far.
Four votes, out of nine, is the real threshold
Four justices have to vote to grant certiorari before a case is even heard — a real, specific internal rule (“the rule of four”) that determines which cases actually get a hearing, out of thousands of petitions filed each year.
Written arguments, then spoken ones, then a written ruling
Parties and outside groups (amici) file written briefs, lawyers then answer questions at oral argument, and the Court eventually issues written opinions explaining both the judgment and the legal reasoning behind it.
Not All Opinions Carry the Same Weight
Majority
The opinion that speaks for the Court and controls how lower courts apply the ruling in future cases.
Concurrence
A justice agrees with the outcome, but explains a different or narrower legal path to get there.
Dissent
A justice explains why they believe the Court reached the wrong result, or the wrong reasoning.
The “controlling rule” isn’t always obvious from the final vote count
A common misconception is that a Supreme Court decision’s meaning is simply whatever the majority opinion states. When the Court is fractured across multiple opinions reaching the same result through different reasoning, the actual controlling legal rule for future cases can depend on complex analysis of which reasoning commanded a genuine majority — not just the headline outcome. A close vote count doesn’t always mean a clear, single rule for lower courts to apply.
