A “1” will appear in this variable if the majority opinion effectively says that the decision in this case “overruled” one or more of the Court’s own precedents. Occasionally, in the absence of language in the prevailing opinion, the dissent will state clearly and persuasively that precedents have been formally altered: e.g., the two landmark reapportionment cases: Baker v. Carr, 369 U.S. 186 (1962), and Gray v. Sanders, 372 U.S. 368 (1963). Once in a great while the majority opinion will state—again in so many words—that an earlier decision overruled one of the Court’s own precedents, even though that earlier decision nowhere says so. E.g, Patterson v. McLean Credit Union, 485 U.S. 617 (1988), in which the majority said that Braden v. 30th Judicial Circuit of Kentucky, 410 U.S. 484, 35 L Ed 2d 443 (1973) overruled a 1948 decision. On the basis of this later language, the earlier decision will contain a “1” in this variable. Alteration also extends to language in the majority opinion that states that a precedent of the Supreme Court has been “disapproved,” or is “no longer good law.”

Note, however, that alteration does not apply to cases in which the Court “distinguishes” a precedent. Such language in no way changes the scope of the precedent contained in the case that has been distinguished.

In addition to following these rules, we consulted several sources. Again, the Congressional Research Service’s Constitution of the United States of America: Analysis and Interpretation (CONAN) (congress.gov/constitution-annotated) was most helpful.

Do not assume that each record of a given case indicates the formal alteration of a separate precedent. A given citation may have several docket numbers, each of which is governed by a single opinion in which only one precedent was altered. Conversely, an opinion in a citation with a single docket number may alter a whole series of Supreme Court precedents. To determine the number of altered precedents, carefully read the prevailing opinion in each citation that has an entry in this variable.