"Presents organizational characteristics, demands, and outcomes of movement's efforts in three historical sequences - 1972-79, 1980-86, and 1987-90. Details cases of land invasions, demands for water tariff reductions, confrontations between PRI-controlled unions and democratic leaders, and street vendors' fights with municipality. Considers role of political parties and evaluates Programa Nacional de Solidaridad"--Handbook of Latin American Studies, v. 57.