Despite ongoing efforts to bridge gender disparities, women continue to be underrepresented in political spheres. This paper proposes a novel explanation for the female disadvantage in electoral success, focusing on politicians’ capacity to broaden their electoral base and appeal to voters from opposing parties. Drawing on Swiss elections, this paper leverages various aspects of the electoral system. In Switzerland, the electoral process is characterized by open lists, allowing voters to select candidates within their preferred party, and cross-voting, enabling them to choose candidates from other party lists. Additionally, electoral registers provide data on the number of preference votes garnered by each candidate, categorized by the voter’s preferred party. The analysis reveals that individual preference votes play a pivotal role in driving gender disparities in candidates’ electoral achievements. While the gender gap in preferences expressed by supporters of a particular party is less robust, male politicians outperform their female counterparts significantly in collecting preference votes through cross-voting. This implies that male politicians are more skilled at persuading voters from rival parties. These findings, motivated by various underlying mechanisms, carry considerable policy implications concerning the approach to addressing gender inequalities in politics.