Senatorial decision making: II. Prediction

A prediction model for individual voting behavior in the United States Senate is developed. It's predictors are based upon the results of a three-mode factor analysis of 419 roll calls from 1964 through 1969. The model is the multiple logistic and it is tested and validated on 18 roll calls from 1970. The parameter estimation and the validation is conducted through the use of Tukey's Jackknife. Generally, the fit is quite good, despite the fact that the test roll calls were chosen for their difficulty. An especially careful analysis is done on the nomination of G. Harrold Carswell as Associate Justice of the U.S. Supreme Court in which the votes of 94 percent of the voting Senators were correctly predicted.