The article examines whether female political candidates are disfavored in terms of persuasiveness potential based on their expertise and trustworthiness. Using a Bayesian argumentation paradigm in which candidates endorse policies, this study shows that male voters regard female candidates as less persuasive than male candidates. A controlled between-subjects experiment among 202 potential voters in the United States suggests that female election candidates are subject to sex biases in two central ways. First, despite agreeing on their trustworthiness and expertise, male voters find highly credible female candidates less persuasive than identical male candidates. Second, female candidates are affected more adversely if they are perceived as lacking in trustworthiness. Male candidates, on the other hand, are affected more negatively if they are perceived as lacking in expertise. Whereas perceived lack of expertise is relatively easy to repair, trustworthiness may be difficult to regain once it is lost. In a political environment in which attack ads are prevalent, this may carry a greater negative impact for female candidates.