Does the issue content of campaign appeals mobilize particular subsets of voters? We examine whether issue content interacts with the interests and agendas of issue publics, focusing on the relationship between campaign messages and the turnout of senior citizens, veterans, and parents. Our analysis matches Current Population Survey respondents to media markets and then to relevant campaign advertising data in the 1998, 2000, and 2002 elections. We find that issue-specific campaign messages are not associated with higher turnout among senior citizens or veterans and are associated with only a small increase in turnout among parents. Our results suggest that campaign effects vary in their magnitude and importance for the mobilization of issue publics.