In Peru, home to liberation theology's founder, Gustavo Gutierrez, John Paul named as archbishop of Lima a member of the ultra-conservative Opus Dei organization, Juan Luis Cipriani, in 1999. Two years later, the pope elevated Cipriani to cardinal, one of only two Opus Dei members to receive such high ranking. Cipriani remains in the position today.
"Not surprisingly, Francis has a much deeper, more nuanced understanding of Latin America," said Father Thomas Reese, like Francis a Jesuit, and a veteran commentator on the Vatican.
Francis has in fact sought to revive liberation theology in its pastoral application -- not political but in what theologians call "base community" work in the region's slums and marginalized areas.
The first pope from the Americas has drawn on his own experience. As a bishop and later cardinal in his native Buenos Aires, Francis often ministered to the poor, and he instructed the priests under his command to do the same. If they returned without mud on their shoes, the man then known as Father Jorge Mario Bergoglio would say they had failed in their mission.
"Experimentation was a dirty word" for many traditional clergy after the Second Vatican Council, which instituted many progressive reforms in the church in the mid-1960s, Reese said. "Not for Francis."
Francis became pope in March 2013, after Benedict broke centuries of tradition and resigned. In addition to this week's trip, his Latin American voyages include Brazil in 2013; Ecuador, Bolivia and Paraguay in 2015; Mexico in 2016, and Colombia last year.
Latin America remains the most Catholic continent, home to roughly 40 percent of the world's Catholics, or more than 500 million people. But it has been steadily losing the faithful. In Chile, for example, a poll this month by the Santiago-based think tank Latino barometro showed that the number of Chileans calling themselves Catholic fell to 45 percent last year, from 74 percent in 1995.
Perhaps most startling was the number now calling themselves atheist, agnostic or without a religion: 38 percent. (Even in relatively secular United States, the average is 22 percent.)
Despite his star power, Francis may not be able to stanch the hemorrhaging of church membership which has gone on for so long and had so many causes, said Andrew Chesnut, chairman of the Catholic Studies department at Virginia Commonwealth University.
He noted that losses in Chile actually accelerated in the last five years, following outrage over the case of Father Fernando Karadima, whom the Vatican accused of molesting boys for years following an investigation in 2011. Francis came under criticism for allowing a bishop -- said to have been mentored by Karadima -- to assume leadership of a diocese in southern Chile.