Published online by Cambridge University Press: 25 January 2021
Does state political ideology change over time? Brace et al. (2004, 537) say no, based on their analysis of three longitudinal measures of state citizen ideology: Berry et al.‘s (1998) indicator that relies on election results and congressional roll call votes, and two indicators that Brace et al. construct from ideological self-placement items, one using GSS and ANES survey results, and the other employing surveys conducted by CBS/New York Times. The authors imply that the ideological stability they detect precludes the possibility that state citizen ideology influences state policy. However, this implication stems from Brace et al.‘s definition of meaningful ideological change as differences in the relative ideology of states over time rather than absolute changes in ideology within states. We contend that this argument is both logically and methodologically flawed. Brace et al. maintain that their CBS/New York Times and GSS/ANES indicators are valid measures of state citizen ideology, but that the Berry et al. indicator is not. To assess this claim, it is crucial to distinguish between ideological self-identification (or symbolic ideology) and policy mood (or operational ideology). We find that the Berry et al. measure is a valid indicator of policy mood, but that it is invalid as a measure of self-identification. In contrast, the CBS/New York Times and GSS/ANES measures are invalid as indicators of policy mood, and while they are valid indicators of self-identified ideology, they are highly unreliable. Although a measure of self-identified ideology can be useful for answering some research questions, we contend that an indicator of policy mood is more appropriate when studying the impact of public opinion on public policy, and we reiterate our confidence in using the Berry et al. (1998) measure for that purpose.