In light of the long histories of racial violence, discrimination, and organized protest by racial and ethnic minority groups in established democracies, it is imperative to examine how minority groups can achieve greater voice in the regular channels of the democratic process. In this paper we compare the inclusion of racial and ethnic minorities in political parties and the national legislatures of the U.S. and Britain. There are few previous comparative studies on this topic, and the broad comparative literature on numerical representation often focuses on theories of socialization and increasing the pool of applicants. We examine an influence that previous scholars have often neglected: the role of political parties in shaping minority representation. We highlight some conditions under which minority groups may achieve gains. Certain political and institutional ‘opportunity structures’ create incentives for under-represented groups to pursue top-down or bottom up strategies in their efforts for democratic inclusion.