The effect of negative campaigning on voter turnout has been a major focus of research in recent years. The general finding from this large literature is that negative campaigning does not depress voter turnout overall; however, it may still be that certain portions of the electorate are differentially mobilized or demobilized by negativity. In particular, scholars have neglected to examine whether men and women react differently to campaign attacks. This article begins by showing that evidence drawn from a variety of relevant fields outside of political science point toward the general expectation that men will be mobilized by negativity to a greater degree than women. Associated hypotheses are then tested using data from both real campaigns and experiments. In each analysis, the evidence supports the hypothesis that a “negativity gap” exists. Specifically, men are disproportionately mobilized by the most negative campaign messages as compared to women. Partisanship is also found to interact significantly with gender and message tone to affect the likelihood of voting. These results highlight the importance of studying subgroup differences when establishing the effects of campaign tone on the public.