In the Reagan era, conservative Republicans felt they had a powerful ally in Pope John Paul II, whose forceful anti-communism and anti-abortion stances played out in American politics.
Today's conservatives are apprehensive about Pope Francis, who has changed the tone and culture, not the doctrines, of the Catholic Church in less than two years as pontiff. He stresses, with passion and authenticity, a commitment to addressing poverty and income inequality more than the social issues that have dominated much of the Catholic debate in America.
John Carr, a former top official of the U.S. Conference of Catholic Bishops, notes that Francis's message on abortion is "no obsession, no retreat."
The pope helped broker the recent thaw in U.S.-Cuban relations, to the consternation of conservatives such as Florida Senator Marco Rubio. Francis now is determined to make addressing climate change a moral imperative for the world's 1.2 billion Catholics.
This doesn't mean that Francis is the poster pope for liberal Democrats: "He's challenging everybody," says Carr, now director of the Initiative on Catholic Social Thought and Public Life at Georgetown University. "Most Democrats haven't been talking about poverty."
He suggested that Francis's impact is starting to change the conversation among Democrats, along with some conservative Republicans, such as House Ways and Means Committee Chairman Paul Ryan of Wisconsin.