When Argentina legalized same-sex marriage in 2010, Pope Francis was at the helm of the nation’s Catholic Church, which opposed the law. But as pope, on a flight back to Rome from Rio de Janeiro, where he celebrated World Youth Day in August, he said to reporters: “If someone is gay and he searches for the Lord and has goodwill, who am I to judge?”

Technically the substance of his words wasn’t new: The church has always proclaimed mercy for all. But the statement created excitement among liberals and concern among conservatives, which all intensified when, in a subsequent interview with the Italian Jesuit journal La Civiltà Cattolica, he blasted an obsession with culture-war issues: “We cannot insist only on issues related to abortion, gay marriage, and the use of contraceptive methods.”

“It sent a message that didn’t sit well with a lot of pro-lifers,” says William Donohue, president of the Catholic League for Religious and Civil Rights, who says the pope’s off-the-cuff style has confused many conservatives. He personally doesn’t believe the pope is a “closet left-wing secularist.” Still, he says, liberal American Catholics, who once selectively ignored papal statements that went against their ideologies, now line up behind the pope and point at the right for defending church teachings. “The left smells a certain victory right now,” he says.

In many ways, the pope’s positions on these issues reflect his origins in Latin America, where the terms liberal and conservative have different meanings than they might in the United States, Africa, or Europe. Latin Americans tend to be conservative on issues of sexual morality, for example, but more liberal on questions of economy, war, and environment.

John Allen Jr., a longtime Vatican observer for the National Catholic Reporter, says this pope is appealing to the big Catholic “middle,” both from the developing world, where most Catholics live – Latin America has the largest share of Catholics in the world, with 425 million – and Europe and the US, where Catholics have strayed because they disagree with church dogma. In this Pope Francis differs from his predecessor, Pope Benedict, who envisioned a more orthodox church, even if it was smaller. “He wants to project a more merciful and compassionate face of the church,” says Mr. Allen. “That is the agenda of the Catholic middle.”