What must occur for a Supreme Court case to become a precedent?

For a Supreme Court case to establish a precedent, it is essential that the majority of justices agree on the decision. This majority ruling creates a binding interpretation of the law that lower courts are required to follow in similar future cases. The principle of stare decisis, which means to stand by things decided, relies on this majority consensus to ensure consistency and stability in the law.

While a unanimous decision can also serve as a strong precedent, it is not a requirement. Similarly, public opinion, while it may influence justices or reflect societal values, does not affect the legal standing of a ruling in establishing precedent. Additionally, the origin of the case—whether from federal statutes, state law, or other sources—does not inherently determine its ability to serve as precedent; rather, it is the decision made by the justices that is crucial. Therefore, the agreement of the majority of justices is what truly enables a Supreme Court ruling to shape the law moving forward.