This article examines the role of the Supreme Court in the development of the Mexican political system. The judiciary provided an important source of regime legitimation, as it allowed for the consolidation of a state of legality and a claim to constitutional rule of law, at least in discourse. However, the judiciary was in effect politically subordinated to the logic of dominant party rule through both specific constitutional reforms since 1917 that weakened the possibility of judicial independence and a politics of institutional and political co-optation. The constitutional reform of 1994 has significantly altered the nature of the relationship between the executive and the Supreme Court.