---
title: "Certiorari — AP Gov Definition, Rule of Four & Exam Guide"
description: "Certiorari is the Supreme Court's discretionary petition to review lower-court rulings, granted by four justices. Key to Topic 2.8 and judicial review on AP Gov."
canonical: "https://fiveable.me/ap-gov/key-terms/certiorari"
type: "key-term"
subject: "AP US Government"
unit: "Unit 2"
---

# Certiorari — AP Gov Definition, Rule of Four & Exam Guide

## Definition

Certiorari (a "writ of cert") is the petition the Supreme Court grants to review a lower-court decision, requiring agreement of four justices (the rule of four); it lets the Court choose only cases raising significant federal or constitutional questions under its Article III appellate jurisdiction.

## What It Is

Certiorari is the gatekeeping tool of the [Supreme Court](/ap-gov/key-terms/supreme-court "fv-autolink"). When a party loses in a federal circuit court or a state supreme court, they don't automatically get a hearing at the Supreme Court. Instead, they file a petition for a [writ of certiorari](/ap-gov/key-terms/writ-of-certiorari "fv-autolink"), basically a formal request asking the Court to take the case. If at least four of the nine justices agree to hear it (the **rule of four**), the Court "grants cert" and orders the lower court to send up the record.

The Court receives thousands of cert petitions every term and grants only a tiny fraction, usually cases that present major constitutional questions, conflicts between [circuit courts](/ap-gov/key-terms/circuit-courts "fv-autolink"), or important federal issues. That discretion is the point. It lets the Court concentrate its power of judicial review on nationally significant disputes rather than re-trying every appeal. Denying cert is not a ruling on the merits; it just leaves the lower court's decision in place.

## Why It Matters

Certiorari lives in **Topic 2.8 (The Judicial Branch)** in [Unit 2](/ap-gov/unit-2 "fv-autolink"): Interactions Among Branches of Government. It supports learning objective **2.8.A**, which asks you to explain [judicial review](/ap-gov/key-terms/judicial-review "fv-autolink") and how the judiciary checks the other branches. Article III gives federal courts their authority, and Federalist No. 78 argues that an independent judiciary is the "least dangerous" branch precisely because it exercises judgment, not force. Certiorari is how that judgment works in practice. By choosing which cases to hear, the Court decides when and where to deploy judicial review against Congress, the president, or the states. If you can't explain how a case reaches the Supreme Court, you can't fully explain how the Court checks the other branches.

## Connections

### [Appellate Jurisdiction (Unit 2)](/ap-gov/key-terms/appellate-jurisdiction)

Certiorari is the mechanism; [appellate jurisdiction](/ap-gov/key-terms/appellate-jurisdiction "fv-autolink") is the authority. Article III gives the Court appellate jurisdiction over most federal questions, and cert petitions are how the Court selects which of those appeals it will actually hear.

### [Article III of the Constitution (Unit 2)](/ap-gov/key-terms/article-iii-of-the-constitution)

Article III creates the Supreme Court and grounds its power, but it says nothing about cert or the [rule of four](/ap-gov/key-terms/rule-of-four "fv-autolink"). Those are practices the Court and Congress developed to manage the caseload, which is a great example of constitutional structure being filled in over time.

### [binding precedent (Unit 2)](/ap-gov/key-terms/binding-precedent)

Cert decisions shape [precedent](/ap-gov/key-terms/precedent "fv-autolink"). When the Court denies cert, the lower-court ruling stands but binds only that circuit. When it grants cert and rules, the decision becomes binding precedent for the entire country, which is why circuit splits often trigger a grant.

### [Citizens United v. FEC (Unit 3)](/ap-gov/key-terms/citizens-united-v-fec)

Every required Supreme Court case you study, from Brown to Citizens United, reached the Court through this process. Granting cert in Citizens United is what turned one nonprofit's campaign-finance dispute into a nationwide First Amendment precedent.

## On the AP Exam

Certiorari shows up most often in multiple-choice questions about how the judicial branch operates, asking things like how a case reaches the Supreme Court, what the rule of four means, or what a denial of cert actually does (it leaves the lower ruling intact, it does not affirm it). No released FRQ has centered on the word "certiorari" itself, but it matters for the SCOTUS Comparison FRQ, where you explain how a non-required case relates to a required one. Knowing that the Court chose to grant cert helps you frame why the case raised a significant constitutional question. In a Concept Application or argument essay about checks and balances, cert is strong evidence that the Court controls its own agenda, which is part of the judicial independence argument from Federalist No. 78.

## certiorari vs judicial review

Judicial review is the power to strike down laws and executive actions that violate the Constitution, established in Marbury v. Madison. Certiorari is just the doorway, the process for deciding whether to hear a case at all. The Court grants cert first, then it may (or may not) exercise judicial review in its ruling. Granting cert never means the Court has decided anything about the merits.

## Key Takeaways

- Certiorari is the discretionary petition process the Supreme Court uses to choose which lower-court decisions it will review.
- Under the rule of four, only four of the nine justices need to agree for the Court to grant cert and hear a case.
- Denying cert is not a ruling on the merits; it simply leaves the lower court's decision in place for that circuit.
- The Court grants cert in only a small fraction of the thousands of petitions it receives, focusing on major constitutional questions and circuit splits.
- Cert is how the Court controls its agenda, which connects directly to LO 2.8.A and the judicial independence argument in Federalist No. 78.
- Every required AP Gov Supreme Court case, from Brown v. Board to Citizens United, reached the Court through a granted writ of certiorari.

## FAQs

### What is certiorari in AP Gov?

Certiorari is the petition a party files asking the Supreme Court to review a lower-court decision. If four justices agree (the rule of four), the Court grants the writ and hears the case. It's the main way cases reach the Supreme Court under its Article III appellate jurisdiction.

### Does denying certiorari mean the Supreme Court agrees with the lower court?

No. A cert denial says nothing about the merits. It just means fewer than four justices voted to hear the case, so the lower court's ruling stands, but only as precedent within its own circuit, not nationwide.

### How is certiorari different from judicial review?

Certiorari is the case-selection process; judicial review is the power to strike down unconstitutional laws and actions. The Court grants cert to take a case, then may exercise judicial review when it decides that case. Marbury v. Madison established judicial review, not certiorari.

### How many justices does it take to grant cert?

Four of the nine justices, known as the rule of four. Notice that's less than the five-vote majority needed to actually win a case, so a minority of the Court can force a case onto the docket.

### Why does the Supreme Court hear so few cases?

Because cert is discretionary. The Court receives thousands of petitions each term and grants only a tiny fraction, prioritizing significant constitutional questions and conflicts between circuit courts. This lets it focus judicial review on nationally important issues instead of routine appeals.

## Related Study Guides

- [2.8 The Judicial Branch](/ap-gov/unit-2/judicial-branch/study-guide/y7kYkIyrT8DYX1Ud7Y75)

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