“…Clausen, 1973;Wilcox and Clausen, 1991), while recent work using sophisticated MDS techniques (Poole and Rosenthal, 1997) has suggested that there is one overwhelmingly predominant factor in historical patterns of congressional roll voting and that a two-dimensional representation accounts for almost all the variance. 1 Similarly, Schubert's (1974, Chapter 7) work on the Supreme Court using a form of MDS (smallest space analysis) argues for one fewer dimension than does his earlier work on factor analysis of court decisions (Schubert, 1965, while more recent authors who use factor analysis (Dudley and Ducat, 1986;Ducat and Dudley, 1987) also find more dimensions in Supreme Court decisions than those who use MDS (Grofman and Brazill, in press). Similarly, some authors who use factor analysis to study the dimensionality of voters in the US have found separate loadings for pro-Democrat and pro-Republican dimensions rather than a unidimensional structure with strong Democratic supporters on one side and strong Republican supporters on the other (Weisberg, 1980).…”