The impact of what judges decide is a crucial part of what is studied by those sharing a political rather than only a legal perspective on the United States Supreme Court. It has become important as we have shifted our attention from “output, which is the decision of the Court including its orders and statement of policy” to consideration of “outcome, which is the final results or impact of output” (Barth, 1968: 315, note). This development is much more recent than the beginnings of the political perspective on the courts. Explicit attention to impact, backed by studies of impacts of particular decisions, is less than twenty years old, dating from the aftermath of Brown v. Board of Education (1954), which made political scientists aware that compliance with decisions of the Supreme Court was neither automatic, immediate, nor uniform. As Krislov (1963: 7) has remarked, from the standpoint of Court process, the decision in Brown v. Board of Education has had its greatest effect in educating “students as to the limits and operations of the court system generally.”