Beyond the running tally: Partisan bias in political perceptions

I examine the impact of long-term partisan loyalties on perceptions of specific political figures and events. In contrast to the notion of partisanship as a simple "running tally" of political assessments, I show that party identification is a pervasive dynamic force shaping citizens' perceptions of, and reactions to, the political world. My analysis employs panel data to isolate the impact of partisan bias in the context of a Bayesian model of opinion change; I also present more straightforward evidence of contrasts in Democrats' and Republicans' perceptions of "objective" politically relevant events. I conclude that partisan bias in political perceptions plays a crucial role in perpetuating and reinforcing sharp differences in opinion between Democrats and Republicans. This conclusion handsomely validates the emphasis placed by the authors of The American Voter on "the role of enduring partisan commitments in shaping attitudes toward political objects."