Stare Decisis and Precedent

Stare decisis, Latin for "to stand by things decided," is the practice of courts following their own prior rulings. It is not a rigid rule that no decision can ever be revisited. It is closer to a strong presumption, one that can be overcome, and understanding how it works means separating two different senses of the word "precedent."

Vertical precedent and horizontal precedent

Vertical stare decisis is the straightforward half: a trial court must follow the rulings of the appeals court above it, and every federal court must follow the Supreme Court's rulings on federal law. There is no discretion here. A lower court that disagrees with binding precedent still has to apply it.

Horizontal stare decisis is the harder half, because it describes a court, including the Supreme Court itself, following its own past decisions even though nothing above it forces that outcome. The Supreme Court is not bound by its own precedent the way a lower court is bound by the Supreme Court's precedent. It can overrule itself. The question horizontal stare decisis raises is not whether the Court has the power to do that, but when it should.

What the Court looks at before overruling itself

In Janus v. American Federation of State, County, and Municipal Employees, decided in 2018, the Court restated and applied the factors it weighs before overruling one of its own constitutional precedents: the quality of the prior decision's reasoning, how workable the resulting legal standard has been in real cases, how consistent the decision is with other related decisions, factual or legal developments since the decision was handed down, and the reliance interests that have built up around it. Applying those factors, the Court in Janus overruled a 1977 precedent that had allowed public-sector unions to charge non-member employees agency fees, concluding that stare decisis did not require sticking with a decision it found poorly reasoned and unworkable.

The same underlying factor list is not new to any one case, and it does not always point toward overruling. In Planned Parenthood v. Casey, decided in 1992, the Court applied a similar set of considerations, workability, reliance, doctrinal developments, and changes in the factual premises underlying the earlier decision, and used them to decline to overrule Roe v. Wade. The factors are a framework for weighing whether to keep or discard precedent; they do not by themselves dictate which way the scale tips.

Dobbs and the limits of reliance

Thirty years after Casey, the Court revisited the same question in Dobbs v. Jackson Women's Health Organization, decided in 2022. Applying an overruling framework much like the one Janus had described, the Court held that "Roe and Casey are overruled," returning the authority to regulate abortion "to the people and their elected representatives." Dobbs is the most prominent recent example of the Supreme Court overturning a decades-old constitutional precedent, and it shows horizontal stare decisis being overcome even where, as in Casey, the same factors had once been read to support keeping the precedent in place.

Whether Dobbs applied those factors faithfully, or whether the same considerations should have led to the opposite result, was contested on the Court itself. The Dobbs majority concluded that Roe and Casey were poorly reasoned, unworkable, and out of step with related doctrine, and that reliance interests did not require preserving them. The Dobbs dissent argued the majority undervalued reliance and stability, and that overruling a precedent tied to such weighty personal decisions demanded more than the majority gave it. That disagreement is a genuine, ongoing one among judges and scholars: reasonable people looking at the same five factors, quality of reasoning, workability, doctrinal consistency, changed circumstances, and reliance, can and do reach opposite conclusions about how much weight each deserves in a given case. Stare decisis does not eliminate that judgment call; it structures it.