The dilemma of constitutional mobilization: The housing and the environmental social movements at the Chilean Constitutional Convention.

This article analyzes the role and strategies of independent social movements during Chile's 2021–2022 constitutional change process, focusing on the socio-environmental movement and the pobladores (housing) movement. For the first time, activists from these movements participated as representatives in the Constitutional Convention, successfully incorporating many of their long-standing demands into the proposed draft constitution, which was ultimately rejected by 62% of voters in the ratification referendum. Through qualitative research, the study identifies four stages of constitutional mobilization—formation, participation, norm drafting, and negotiation—and highlights how favorable political opportunities and internal cohesion enabled these movements to influence the constitutional debate. However, the movements' limited negotiation with centrist political actors and a misreading of broader public opinion contributed to the rejection of the draft, illustrating the complex relationship between social movements, institutional politics, and constitutional legitimacy. The Chilean case underscores the importance of inclusive deliberation, negotiation, and broad citizen participation in constitution-making processes to secure majority support.