Constitutional judges consider matters relevant for the protection of rights, political competition, and the exercise of power. Why, however, do some constitutional courts stand out for their work regarding rights enforcement, whereas others distinguish themselves for their role in arbitrating disputes between political actors? In Latin America, for instance, the Colombian Constitutional Court and the Costa Rican Sala Cuarta have been very active in the protection of rights (e.g., Uprimny Yepes 2006; Wilson 2005), whereas the Mexican Supreme Court and the Chilean Constitutional Tribunal have not. However, the two latter courts have been efficient arbiters regulating political competition in their respective countries (e.g., Magaloni 2003; Domingo Villegas 2005; Scribner 2004).

Institutions that are thought to influence the independence and power of constitutional judges are often invoked to explain their behavior (e.g., Rosenberg 1991) and are one of the three components of the strategic account of judicial behavior (cf. Epstein and Knight 1998, and the introduction to this volume). This is the main rationale behind changes in basic rules designed to insulate judges from undue political pressure (e.g., appointment, tenure, and removal institutions) and to give them power to intervene in policy making (e.g., their powers of judicial review). More recent institutional arguments point to specific institutional features within the two broad dimensions of independence and power to explain why and to what extent constitutional judges tend to devote relatively more time to arbitrating conflicts between branches and levels of government or to upholding rights.