Why do parties continue to nominate overwhelmingly white male candidate lists? Over recent decades, attitudes about gender and racial equality have become more egalitarian across many democracies. Yet, the political representation of historically marginalized groups continues to lag behind, even in countries which have adopted institutions like quotas for women and ethnic minorities. We argue that one reason homogeneous candidate lists persist is that parties – even those on the left – respond to political conservatism in the electorate. That is, even as voters have grown less sexist, racist, and homophobic over time, their political views have tilted right and far-right over the same period. In this context, parties might be unwilling to diversify, given diverse lists are associated with more progressive politics (e.g, Adams et al. ND). To test our argument, we leverage official candidate data from the 2016, 2020, and 2024 municipal elections in Brazil. Brazil offers a compelling case: it has an incredibly ethnically diverse population, the state has legislated quotas and reserved campaign funds for historically marginalized groups, and voters largely support these efforts. Yet, white men still dominate candidate lists. Importantly, the data we employ include rare self-reported information about all candidates’ sex and race/ethnicity. We test theories about the conditions under which lists remain homogeneous by matching this information with party- and municipal-level data. The findings have important implications for the conditions under which inclusive representation can be achieved in democracies.