AP® United States Government and Politics review sheet from Aim for Five (aimforfive.com/gov/units/2/2-9)
Unit 2 · Topic 2.9
2.9 The Role of the Judicial Branch
Courts usually follow precedent, earlier rulings on similar questions, under the principle of stare decisis, which keeps the law stable and predictable. But when the Court's membership and ideological balance change, it may set new precedents or overturn old ones, as Brown v. Board of Education did to Plessy v. Ferguson. The Court's legitimacy depends on the public seeing its rulings as law, not politics.
Key terms
- precedent
- stare decisis
- overturning precedent
- ideological balance of the Court
Precedent and stare decisis
A precedent is an earlier court ruling that guides how later cases with similar issues are decided. Stare decisis is Latin for “let the decision stand.” It's the principle that courts should generally follow precedent.
Lower courts must follow Supreme Court precedent. The Supreme Court usually follows its own precedents too, but it isn't strictly bound to and can overrule itself.
Why courts follow precedent
- Stability: people, businesses and governments can plan around settled law.
- Fairness: similar cases get similar treatment, no matter who the judge is.
- Legitimacy: if rulings flipped every time the Court's membership changed, the law would look like politics, and the public might stop accepting the Court's decisions.
- Efficiency: courts don't have to rethink every question from scratch.
When precedent gets overturned
The Court has overruled itself well over a hundred times. Justices who want to overrule a precedent usually argue that it was badly reasoned, that it has proved unworkable, or that facts and society have changed so much that its foundation no longer holds.
The most famous example: Plessy v. Ferguson (1896) upheld racially segregated railroad cars under the doctrine of “separate but equal.” In Brown v. Board of Education (1954), a unanimous Court ruled that separate public schools are “inherently unequal,” rejecting Plessy's reasoning for education.
| Old precedent | Overturned by | What changed |
|---|---|---|
| Plessy v. Ferguson (1896) | Brown v. Board of Education (1954) | Segregated public schools violate equal protection |
| Betts v. Brady (1942) | Gideon v. Wainwright (1963) | States must provide lawyers to poor felony defendants |
| Bowers v. Hardwick (1986) | Lawrence v. Texas (2003) | States can't criminalize private, consensual same-sex relations |
| Roe v. Wade (1973) | Dobbs v. Jackson Women's Health Organization (2022) | The Constitution doesn't protect a right to abortion; the issue returns to elected lawmakers |
Ideological balance and new appointments
The Court's direction depends heavily on who sits on it. When a president appoints a justice whose views differ from the person being replaced, the ideological balance can shift, and questions that seemed settled may be reopened. That's why Supreme Court vacancies spark such intense confirmation fights (2.5).
This creates a lasting debate. Supporters of an overruling call it correcting a mistake; critics call it politics replacing law. The same people can be on different sides depending on the precedent in question. Either way, the Court's legitimacy depends on public belief that rulings rest on legal reasoning.
Worked examples
Try each one yourself first, then open the solution.
- Example 1
Explaining a shift in precedent
Explain how a change in the Supreme Court's membership could lead to a precedent being overturned, and describe one argument against overturning it.
Show the solutionHide the solution
- Step 1: Start with the mechanism: justices serve for life, so the Court changes only when vacancies open. A president then nominates someone who shares their judicial philosophy, and the Senate confirms.
- Step 2: Explain the effect: if the new justice tips the Court's ideological balance, a majority may now believe an earlier precedent was wrongly decided and vote to overrule it.
- Step 3: Give the counterargument: stare decisis values stability and legitimacy. Overruling precedent after a membership change can make the Court's decisions look political and unsettle laws people relied on.
Answer: New appointments can change the Court's majority, which may then overrule precedent it views as wrong. Critics respond that stare decisis protects stability and the Court's legitimacy.
Common mistakes
- Saying the Supreme Court can never overturn its own precedents. Stare decisis is a strong principle, not an absolute rule.
- Saying Brown v. Board overturned Plessy for everything at once. Brown rejected “separate but equal” in public education; later rulings and laws ended segregation elsewhere.
- Confusing precedent with the Constitution itself. Precedent is the Court's interpretation; it can change while the text stays the same.
On the exam
- Questions often ask how stare decisis or ideological shifts affect the Court's decisions. Link appointments to changes in precedent.
- For the SCOTUS comparison, remember that a required case can show the Court overturning an earlier ruling, as Brown did to Plessy and Gideon did to Betts.
Connected topics
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Check yourself
4 questions on 2.9 The Role of the Judicial Branch. Pick an answer to see if you got it, and why.
In Plessy v. Ferguson (1896), the Court upheld state laws requiring racially “separate but equal” facilities. In Brown v. Board of Education (1954), the Court ruled that segregated public schools violate the Equal Protection Clause. Brown best illustrates
A federal district judge writes in her opinion that she thinks a Supreme Court decision was wrongly decided, but she applies it to the case anyway. Her decision best illustrates
Which of the following is the strongest argument for following stare decisis?
In Betts v. Brady (1942), the Supreme Court held that states did not always have to give poor defendants a lawyer in felony cases. In Gideon v. Wainwright (1963), the Court ruled that they must. Which development best helps explain the change?
0 of 4 answered