Political incorporation represents an important and complex trajectory for social movements. Whether that trajectory leads to favorable substantive outcomes or merely to formalistic representation within the polity depends in part on the strategic decisions made by leaders. We have few frameworks, however, for understanding their role in navigating incorporation. This research presents a “niche definition” framework emphasizing strategic differentiation and articulation across political actors in distinct institutional locations sharing common goals. It focuses attention on leaders’ efforts to identify and exploit unique resources and leverage made available through incorporation. Overall, the framework emphasizes the potential for collective strategy and cooperative interorganizational dynamics, thereby expanding possibilities for favorable outcomes of political incorporation. The framework is illustrated through a case study of the Orange County (California) Human Relations Commission from its creation in 1971 to 2001. I trace the long-term challenges and consequences of incorporation through leaders’ definition of successive niches.