This chapter explores the popular organizing that arose in Mexico’s southwest state of Guerrero during the Cold War. It concludes that the movement’s identification with the language of nationalism and economic and social expectations that arose with the revolution of 1910 distinguishes it from many of the contemporary Marxist-inspired movements in Latin America. Following a series of government assaults on peaceful protesters demanding democratic inclusion, the teacher-activists who had led the initial opposition – Genaro Vázquez Rojas and Lucio Cabañas – each founded an armed guerrilla movement. While these both remained small, the chapter argues that they enjoyed the support of a broader base that hid them, fed them, and suffered the consequences of unrestrained government violence. Guerrero was, ultimately, the site of Mexico’s guerra sucia. This history also helps us understand the disappearance of Ayotzinapa’s teachers-in-training in 2014. Those students attended a school distinguished for producing radical opposition leaders since its post-revolutionary inception, including, during the Cold War, Lucio Cabañas.