Most explanations of inequality in political participation focus on costs or other barriers for those with fewer economic, educational, and “cognitive” resources. I argue, drawing on Pierre Bourdieu's work on “political competence,” that social position in the form of income also structures political participation through differences in the sense that one is a legitimate producer of political opinions. I test whether income differences in participation persist net of costs by examining nonparticipation in a setting in which barriers to participation are low: answering political survey questions. Lower-income people are more likely than others to withhold political opinions by saying “don't know” net of differences in education, “cognitive ability,” or engagement with the survey exercise. Further, political “don't know” rates predict voting rates, net of other predictors. Efforts to democratize participation in American politics must attend not only to the costs of involvement but also to class-based differences in individuals' relationship to political expression itself.