On the day Perón returned to Argentina, the clash between Peronist internal factions—right-wing union leaders and left-wing youth from the Montoneros—resulted in the Ezeiza Massacre. Overwhelmed by political violence, Cámpora resigned and Perón won the following September 1973 election with his third wife Isabel as vice-president. He expelled Montoneros from the party and they became once again a clandestine organization. José López Rega organized the Argentine Anticommunist Alliance (AAA) to fight against them and the People's Revolutionary Army (ERP).