With competing assumptions and alternative empirical models, scholars have come to rather different conclusions about the impact of public preferences on the decisions of the U.S. Supreme Court. Some have found the justices to be attentive to mass opinion, while others have judged it to be irrelevant. Across this divide, however, one assumption is widely shared; that is, political scientists generally agree upon how best to measure the Court's outputs. In this analysis, we employ an alternative estimate of the justices’ liberalism, one which we think better reflects the underlying ideological tenor of their policies. With data from 1953 to 1996, we compare time-series models using different indicators of the Supreme Court's aggregate liberalism. Our results suggest that, in addition to being motivated by their own preferences, the justices are highly responsive to public mood, as well.