The Movement Toward Socialism (MAS), officially the Movement for Socialism – Political Instrument for the Sovereignty of the Peoples (Movimiento al Socialismo – Instrumento Político por la Soberanía de los Pueblos), is a Bolivian socialist political party founded in the 1990s from rural social movements, especially coca growers in the Chapare region[1][5][9]. It is rooted in indigenous mobilization and has sought to represent marginalized social sectors, including indigenous peoples, workers, and urban poor, aiming for plurinational unity and sovereignty over Bolivia’s natural resources[1][6]. MAS rose to national prominence when its leader, Evo Morales, a former coca-growers union leader, was elected president in 2005, marking the first time a single party won an outright majority in Bolivian history[1][2]. Under Morales and MAS governance, Bolivia underwent significant transformations: nationalization of key industries such as hydrocarbons and lithium, agrarian reform, redistribution of wealth, and increased social inclusion for indigenous populations[2][6][7]. The party dominated Bolivian politics for two decades, winning four consecutive general elections and municipal contests, reshaping the country’s political landscape by dismantling traditional elites[1][3]. Despite these successes, MAS has faced challenges including internal factionalism between supporters of Morales ("Evistas") and those backing current President Luis Arce ("Arcistas"), who was Morales’s economic architect[1][3]. This conflict culminated in the expulsion of Arce and Vice President David Choquehuanca from the party in 2023 by the Morales-led board, though the expulsion was contested within MAS[1]. Furthermore, Morales himself left MAS in 2025 after being barred from running again, signaling a fragmentation and electoral decline of the party that had dominated Bolivian politics[1][3]. MAS’s hybrid organizational structure combines grassroots rural base control with urban to