This study isolates the impact of certain factors upon the decision making of the United States Supreme Court. Selected group theory methodology is applied to the Court's decisions from 1969 through 1973. The group structure of the Court, the impact of personnel change, and the effect of judicial attitudes on public policy are explored and statistically measured with a chisquare. Schubert's bloc analysis and a Guttman scale are used to order the data. Conclusions include that two stable blocs existed on the Court during these years. Personnel change is demonstrated as causative of alterations in judicial behavior. Seven of eight groups of cases are shown to stimulate values of the Justices. Suggestions are made for further research.