The mass public has become affectively polarized—ordinary Americans increasingly dislike and distrust those from the other party, with negative consequences for politics. Drawing on work in political and social psychology, this paper tests two mechanisms for reducing this discord, both of which have been shown to reduce similar biases in other settings: heightening partisan ambivalence, and using self-affirmation techniques. A population-based survey experiment shows that neither strategy reduces affective polarization in the aggregate. But this null finding masks an important heterogeneity: Heightening partisan ambivalence reduces affective polarization for ideological moderates, but increases such discord for those with more extreme ideological identities. Efforts to depolarize the electorate can make it more deeply divided, with important implications for our understanding of contemporary politics and the durability of affective polarization.