The paper investigates whether the 1976 presidential debates contributed to political participation among all sectors of American society. Evidence was obtained from 353 eligible voters in Madison, Wisconsin, before and after the debates. Effects were evaluated by taking correlations between the level of respondents' exposure to the debates and other media sources and 27 post-debate participation variables. These variables were broadly categorized into five areas: attention and interest, information gain, degree of political participation, strengthening of democratic system values, and changes in vote decision. Equivalence of effect among social sectors was determined by analyzing results for groups according to similarity in age, educational background, and political impact. Results show that debate watching had weak positive effects on participation (voter turnout or campaign activity). Its main impact was indirect through stimulation of discussion and interest in following the media's analyses of the debates. Newspaper readers increased their participation during the debate period, especially among groups who were usually less politically active. Television news viewing and campaign advertising recall had weaker effects. (Author/AV)