The creation of a new, subordinate judicial office within the courts represents a particular kind of reform intended both to increase judicial resources and to insure the flexible development and utilization of those resources. In the case of the U.S. magistrates, concerns about the constitutionality of implementing an authoritative judicial office dictated that Congress grant to the Article III based district judges the formal power to define precisely the tasks and roles of the newly created subordinate judges. Although the district judges possess the formal authority to define the magistrates' roles, the ambiguous guidance from statutory sources and the judges' lack of experience with authoritative judicial subordinates created opportunities for other factors, such as magistrates' expectations and established practices within districts, to influence the development of the subordinates' roles within each courthouse.
Some magistrates may be locked into specific roles because their supervising judges have firm opinions about how subordinate judicial officers ought to be utilized. As the example of District A illustrates, however, magistrates' roles can change, sometimes in ways that directly contradict the district judges' stated intentions, if there are shifts in the composition or quantity of case-processing demands upon the district court. Thus, the broad authority possessed by the magistrates makes them especially flexible resources whose responsibilities can adjust with sensitivity to changing judicial needs, regardless of whether district court officials have formally or rationally planned changes in the subordinates' roles. This adaptive quality of these broadly authoritative, subordinate judges creates the possibility that federal courts can respond flexibly to a variety of pressures without the infusion of resources necessary when the judiciary is composed only of actors (e.g., judges and law clerks) whose responsibilities and authority, although somewhat flexible, are more precisely defined. For example, expectations about the proper judicial behavior and demeanor for district judges, possessed by both the incumbents and the public, may limit or at least hinder judges' ability