In 1961, after the resignation of Jânio Quadros, Vice-President João Goulart, a social-democrat with popular reform proposals, took office. He would, however, rule the country "de facto" only in 1963, after a referendum ended the parliamentary system approved by the Congress to prevent the Military Forces from overthrowing him from office due to his progressive views. During Goulart's government, PSB's president João Mangabeira became Justice Minister. A military coup in 1964 deposed Goulart under charges that he was leading a socialist revolution with his Basic Reforms (Reformas de Base) program. Goulart's biggest political opponent – and coup supporter – was Carlos Lacerda, son of Maurício de Lacerda, founder of PCB who later joined the National Democratic Union (União Democrática Nacional – UDN), an anti-Communist party.