Partisan bias in a sorted party system: A problem of epistemic inequality

Abstract Normative and empirical scholars typically treat partisans’ distrust of their political rivals as a product of individual cognitive biases. But even if bias is inevitable, it is parties’ coalition‐building and messaging strategies that determine who bias is directed toward. This paper argues that the social sorting of party conflict exacerbates the epistemic and democratic harm of partisan distrust by generating distinctive patterns of epistemic inequality. I show that when voters associate parties with particular social groups, members of those groups suffer greater risk of testimonial injustice and related credibility deficits owing to their perceived partisanship. These dynamics are most damaging for members of marginalized groups, as party–group overlap can reinforce the prejudices they already face. Addressing these harms, I argue, requires looking beyond individual partisans to the background features of party systems that shape how elites mobilize group identities and animus in the struggle for office.