As a delegate to the 1971 Constitutional Convention, Raul Manglapus sponsored a resolution that would ban President Marcos from reelection, and his spouse from succeeding him.

Marcos answered that by exercising one-man rule (or, as others put it, a conjugal dictatorship together with his wife Imelda) until his ouster in February 1986. And Manglapus would have been one of the many oppositionists arrested after the declaration of martial law in 1972, if he didn’t happen to be travelling abroad at the time.

Many years of exile in the United States were spent by Manglapus, who was already a prominent politician at the time, in campaigning against the Marcos regime’s fundamentally undemocratic nature, its corruption and excesses. His group, the Movement for a Free Philippines, focused on lobbying in America to persuade the US government to withdraw its support for the dictatorship.

Much admired for his oratorical prowess and intellectual gifts, Manglapus was consistent in his advocacy for reforms in the country’s political and economic system, including land reform and a change from the presidential to the parliamentary system. He authored the Land Reform Code (RA 3844) during his first term as senator (1961-1967). He founded the Christian Social Movement in 1968, and the Progressive Party of the Philippines.

While in the US, he held teaching and research posts at Cornell University in New York, the American University in Washington DC, and the Harvard University Center for International Relations. He also worked for two years with the Carnegie Endowment for International Peace in New York and another two years as president of the Center for Development Policy in Washington DC (1983-1985).

After his return to the Philippines in 1986, Manglapus was elected to the Senate for a second term, then appointed by President Corazon Aquino as her Secretary of Foreign Affairs; he had already served as such under President Carlos P. Garcia in 1957. He remained at his post until 1992.

Manglapus continued to promote political reforms with his involvement in such organizations as the Center for Christian-Muslim Democracy, Christian Democrats International, Democracy International, the United Muslim Democrats in the Philippines, the National Union of Christian Democrats.

He died in Manila in 1999, at the age of 80.