In many respects, Francis’ economic views are consistent with church doctrine and the views of previous popes, though John Paul II spoke more about the benefits of capitalism in the context of his anti-Communist views. But with his humble style and off-the-cuff remarks, Francis is seen as shifting the church’s emphasis and tone.

By playing down issues like abortion and same-sex marriage, the pope has also upended an order in Washington, where conservatives have long viewed the church as an ally.

Mr. Durbin, who attended Catholic schools but, as a senator, switched parishes to avoid being denied communion because of his support for abortion rights, no longer feels “beleaguered by the conservative leadership.” Senator Patrick J. Leahy of Vermont, a Democrat who served as an altar boy from grade school through college, described himself as feeling “liberated” after a recent speech to a university center on Catholic intellectual life brought nary a question about his support for abortion rights. He credited Francis for changing the tone.

“I felt such a relief,” Mr. Leahy said.

Pope Francis is, of course, a religious figure — not a political one — and faith has long mixed uneasily with politics in American public life. John F. Kennedy, the only Roman Catholic president, felt compelled as a candidate to pledge not to take cues from the pope. Today, with evangelical Christians a potent political force, especially among Republicans, talk of God during political campaigns is routine.

Catholics account for about 24 percent of voters; for national candidates, courting them is essential. Since 1972, just one presidential candidate, George W. Bush in 2000, has won the White House without winning the Catholic vote.

Francis has proved his own admonition that “a good Catholic meddles in politics.” His much-publicized comments on homosexuality — “Who am I to judge?” he said when asked about gay priests — provoked Sarah Palin, the 2008 Republican vice-presidential nominee, to say Francis sounded “kind of liberal.” Representative Nancy Pelosi of California, the Democratic leader, who attended an all-girls Catholic high school in Baltimore, said on CNN that with his message of tolerance, “the pope is starting to sound like the nuns.”

Catholic lawmakers in both parties know Francis is not changing church doctrine, including opposition to abortion and same-sex marriage. “I haven’t yet seen anything that departs from Catholic teaching,” said Senator Patrick J. Toomey, Republican of Pennsylvania, an economic conservative.