A pattern analysis of the second Rehnquist U.S. Supreme Court.

The second Rehnquist Court has remained unchanged in composition for 8 yr, resulting in a large temporally stable database. This paper reports on a mathematically objective analysis of this ensemble of rulings aimed at extracting key patterns and latent information. Although the rulings of a nine-justice Court require representation in nine dimensions, smaller spaces describe the Court's actions; e.g., a 2D subspace describes the margins of all decisions, and use of Shannon information shows that the Court acts as if composed of 4.68 ideal justices. Comparison is also made with the 1959-1961 and 1967-1969 Warren Courts. Both Warren Courts have remarkable parallels with the Rehnquist Court. In each instance, we present an optimal mapping of the justices between the Courts, which underscores the similarity in the workings of seemingly dissimilar courts.