In two field studies, we examined whether voters overestimate support for their political party among nonvoters. In Study 1, voters estimated the percentage of votes their party would receive in an upcoming election, and this percentage increased when voters estimated the percentage of votes their party would receive if nonvoters also were to vote. In Study 2, participants overestimated support for their party even when we made them explicitly aware of current levels of this support by presenting them with poll-based forecasts of election results. Furthermore, Study 2 demonstrated that commitment to vote for a specific party predicted the degree of overestimation. Our results imply that highly committed voters are particularly likely to project support for their party onto nonvoters. Implications for the literature on social projection and social identity are discussed.