Public reason liberalism is a normative theory meant to adjudicate citizens’ conflicting beliefs about the right and the good. However, it rests upon controversial and likely mistaken empirical claims about voter psychology and voter knowledge. In political science, there are two major paradigms—populism and realism—about the relationship between voters’ beliefs and political outcomes. Realism holds that most citizens lack the kinds of beliefs and attitudes which public reason liberals believe are normatively significant. If so, then most citizens lack the kinds of ideological disputes which public reason liberalism is supposed to adjudicate. Worse, most citizens lack the kinds of normatively significantly beliefs upon which public justification must rest.