Liberation theory includes a critique of the structural causes of poverty and a call for the church and the poor to organize for social change. Mr. Lee said it was a broad school of thought: Movements differed in different countries, with some more political in nature and others less so. The broader movement emerged after a major meeting of Latin American bishops in Medellín, Colombia, in 1968 and was rooted in the belief that the plight of the poor should be central to interpreting the Bible and to the Christian mission.

But with the Cold War in full force, some critics denounced liberation theology as Marxist, and a conservative backlash quickly followed. At the Vatican, John Paul II, the Polish pope who would later be credited for helping topple the Soviet Union, became suspicious of the political elements of the new Latin American movements.

“All that rhetoric made the Vatican very nervous,” said Ivan Petrella, an Argentine lawmaker and scholar of liberation theology. “If you were coming from behind the Iron Curtain, you could smell some communism in there.”

John Paul reacted by appointing conservative bishops in Latin America and by supporting conservative Catholic groups such as Opus Dei and the Legionaries of Christ, which opposed liberation theology. In the 1980s, Cardinal Joseph Ratzinger — later to become Pope Benedict XVI, but then the Vatican’s enforcer of doctrine — issued two statements on liberation theology. The first was very critical, but the second was milder, leading some analysts to wonder if the Vatican was easing up.

From his 1973 appointment as head of the Jesuits in Argentina, Francis, then 36 and known as Jorge Mario Bergoglio, was viewed as deeply concerned with the poor. But religious figures who knew him then say Francis, like much of Argentina’s Catholic establishment, thought liberation theology was too political. Critics also blamed him for failing to prevent the kidnapping and torture of two priests sympathetic to liberation theology.