Partisan Disagreements Arising from Rationalization of Common Information

Why do opposing partisans sometimes disagree about the facts and processes that are relevant to understanding political issues? One explanation is that citizens may have a psychological tendency toward adopting beliefs about the political world that rationalize their partisan preferences. Previous quantitative evidence for rationalization playing a role in explaining partisan factual disagreement has come from cross-sectional covariation and from correction experiments. In this paper, I argue that these rationalizations can occur as side effects when citizens change their attitudes in response to partisan cues and substantively relevant facts about a political issue. Following this logic, I motivate and report the results of a survey experiment that provides US Republicans and Democrats with information that they will be inclined to rationalize in different ways, because they have different beliefs about which political actors they should agree with. The results are a novel experimental demonstration that partisan disagreements about the political world can arise from rationalization.