Scholars such as Jeffrey Segal and Harold Spaeth contend that U.S. Supreme Court decisions are based primarily upon the ideological beliefs of the justices. However, in this work I show that this conclusion is exaggerated. The aggregation of votes into a summary statistic (the percent liberal rating) and its use by Segal and Spaeth in a regression having only 21 cases creates misleading results. The truth is that political ideology is a fluctuating influence upon the Court. In some areas of civil liberties voting, ideology is a poor explanation of how cases are decided (e.g., core political speech). But in other areas, ideology is a much stronger explanation (e.g., search and seizure). In this work, I investigate whether the clarity of legal commands can explain why the influence of ideology fluctuates so much. My hypothesis is that value voting is inversely related to how clearly a right is designated by legal commands. That is, where statutes or constitutional language clearly designates a claim to liberty, ideology is a weak predictor of votes, but where law is vague and indeterminate in its nomenclature, value-voting rules. This dissertation has both a qualitative and quantitative component. It also relies upon literature that is multi-disciplinary. It accomplishes following: (1) constructs a criteria for rigidity in legal language; (2) selects cases for content analysis that meet the criteria; (3) assesses the relationship between values and votes within the selection using logistic regression analysis; (4) assesses the influence of textual rigidity upon votes cast by each individual justice for all selected cases using logistic regression analysis and (5) re-assess the attitudinal model\u27s goodness of fit for all civil liberties cases in a way that avoids ecological problems and micronumerous cases. The results of this work will show that the influence of political ideology upon judging in the Supreme Court has been overstated in the literature, and that command rigidity is a statistical predictor of judicial votes. In short, law matters
