Stare Decisis—a Latin term that means “let the decision stand” or “to stand by things decided”—is a foundational concept in the American legal system. To put it simply, stare decisis holds that courts and judges should honor “precedent”—or the decisions, rulings, and opinions from prior cases. Respect for precedents gives the law consistency and makes interpretations of the law more predictable—and less seemingly random.
Stare decisis may be simple at its core, but there are nuances and limits in the way it is applied. For example, vertical stare decisis—the idea that the decisions of higher courts take precedence over the decisions of lower courts—is deeply entrenched in the American legal system. This idea is part of what makes the Supreme Court “supreme.” By contrast, horizontal stare decisis holds that prior decisions made by courts at a particular appellate level (such as a federal court of appeals) should provide some precedent for cases heard by courts of the same appellate level. Horizontal stare decisis is generally seen to be less “control” when compared to vertical stare decisis.
Of course, courts often hear cases where following precedent may lead—in the view of the judges for the case—to unjust outcomes. In those cases, the judges may offer reasons or legal nuances to avoid following precedential decisions or to outright overturn prior rulings. For good reason, courts and judges often feel obliged to explain their reasons in such cases. Many rulings are based on specific facts at a given moment in history, and as the nation develops and changes—as a result of new technologies or demographic shifts, for example—the justifications and interpretations of prior decisions may lose support. Perhaps the best-known example of this kind of change is the Supreme Court decision in Brown v. Board of Education (1954), which directly overturned the precedent of Plessy v. Ferguson (1893). Plessy held that “separate but equal” public accommodations did not violate the Constitution. The history of segregation in America, however, proved that “separate” usually did not result in “equal,” and about 60 years later, the Supreme Court recognized that fact and decided in Brown that racially segregated schools violated the Constitution.
Some constitutional scholars propose the idea that certain legal opinions amount to “super precedents”—that are so fundamental to American justice that they are virtually permanent decisions and thus impervious to overruling. The list of so-called super precedents gets debated nearly every time a U.S. Supreme Court justice goes through a Senate confirmation hearing.