Political Behavior, Vol. 24, No. 2, June 2002 ( 2002)
BEYOND THE RUNNING TALLY:
Partisan Bias in Political Perceptions
Larry M. Bartels
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 em-
ploys 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 Amer-
ican Voter on “the role of enduring partisan commitments in shaping attitudes toward
Key words: party identification; Bayesian learning; perceptual bias.
The authors of The American Voter built their account of electoral behavior
in significant part on “the role of enduring partisan commitments in shaping
attitudes toward political objects” (Campbell, Converse, Miller, and Stokes
1960, p. 135). In the simplest caricature of what has come to be called “the
Michigan model,” partisan loyalties are formed early in life, remain perfectly
stable throughout adulthood, and serve as the unmoved movers of more spe-
cific political attitudes and behavior. Thus, evidence of reciprocal effects of
specific political attitudes on party identification (Franklin and Jackson 1983;
Jackson, 1975) and evidence of significant shifts in the aggregate distribution
of party identification (MacKuen, Erikson, and Stimson, 1989) have some-
times been interpreted as empirical challenges to the Michigan framework.
Would-be revisionists have frequently overlooked the fact that Campbell and
Larry M. Bartels, Woodrow Wilson School, Robertson Hall, Princeton University, Princeton,
NJ 08544-1013 (email@example.com).
0190-9320/02/0600-0117/0 2002 Plenum Publishing Corporation