Ideological Values and the Votes of U.S. Supreme Court Justices

It is commonly assumed that Supreme Court justices' votes largely reflect their attitudes, values, or personal policy preferences. Nevertheless, this assumption has never been adequately tested with independent measures of the ideological values of justices, that is, measures not taken from their votes on the Court. Using content analytic techniques, we derive independent and reliable measures of the values of all Supreme Court justices from Earl Warren to Anthony Kennedy. These values correlate highly with the votes of the justices, providing strong support for the attitudinal model.