Classic conceptions of democracy are based, in part, on a vibrant public sphere where citizens are informed and engaged in public deliberation on important topics. Argumentation is central to this vision. Each side builds their case by marshalling the available evidence in support of their preferred conclusion. A rational public, it is assumed, takes in the evidence, evaluates the strengths and weaknesses of the competing positions, and updates their opinions. Unfortunately, recent research in neuroscience and political psychology provides a direct challenge to this vision. Rather than evidence and argument shaping our opinions, our opinions shape our interpretation of evidence and argument. Efforts to reestablish a shared reality must account for individual motivations to discount information that is inconsistent with pre-existing attitudes.