Previous work suggests that observing women officeholders increases women’s political ambition. Yet, jumps in women’s representation in the United States’ “Years of the Woman”—following the Anita Hill testimonies and the election of Donald Trump—are linked to women’s exclusion from political decision-making. Drawing on focus groups with prospective women candidates, we theorize that exclusion when combined with a gendered policy threat increases women’s political ambition. Using survey experiments replicated across different samples, we show that women who read about an all-male city council poised to legislate on women’s rights report increased ambition compared with their pretreatment ambition levels and to women in other treatment groups. Women’s increased sense of political efficacy drives these results. When women’s rights are not under discussion, men’s overrepresentation does not move (or even depresses) women’s ambition. Seeing the policy consequences of their exclusion causes some women to seek a seat at the table.