This study examines the impact of rural grassroots movements on agrarian policy and legal rights expansion in Brazil, Chile and Ecuador in the 1993-2004 period. This work generates insights into when and how it is advantageous for Latin American social movements to enter party and interest group politics rather than continuing direct action. It focuses on the dilemma faced by movement leaders who must advance group demands by interacting with political elites without making compromises that would alienate theirs own grassroots base of support. The dynamic interplay between social movements and political actors is formalized into a model in which leaders use the reliability of their grassroots support to gauge the risks of cooperating with parties, politicians and state agencies. The analysis innovates in bridging a link between social movement resources, opportunities and strategies in the context of newly democratized nations. A comparison of six movements with similar demands but varying degrees of success in the resolution of conflicts illuminates the ways in which public participation by underrepresented groups in civil society affects the quality, accountability and inclusiveness of these democracies. The research methodology will involve semi-structured interviews with MST (Landless Rural Movement) leaders in Brazil, indigenous Mapuche leaders in Chile, and CONAIE (Confederation of Indigenous Nationalities of Ecuador) leaders in Ecuador that will reveal leadership characteristics, organizational structure, cohesiveness of the movement, and the quality and nature of leaders' interaction with members, the wider local population, and political representatives at the local and national level. Interviews with supporters and opponents of the movement in congress as well as key government officials will be also be conducted to assess the political opportunities and obstacles the movement faces at the political level. This material will be supplemented by archival and newspaper analysis. The broader impacts of this study include the following. The findings of this study will be of interest to scholars, students, and policymakers interested in understanding of how underrepresented groups in civil society fare in exerting influence in the policymaking arena. The results of this research wil be disseminated among local, national and international organizations working with grassroots groups and educational institutions exploring civil society issues through the presentations in multidisciplinary conferences and lectures in the U.S. and abroad.