The New York Times Magazine this weekend offers a detailed answer, with an in-depth look at a man who is arguably the leading (and most influential) Catholic intellectual in America.

A snip:

George’s role as an adviser to (these) bishops began more than 20 years ago, when he was a young professor and recent Ph.D. A mutual friend introduced him to the Rev. John Myers, then a bishop in Peoria, Ill., who was working on a pastoral letter about the moral obligations of Catholic voters and politicians. With George’s assistance, Myers wrote a letter laying out the case that abortion, as the taking of a life, was a crime against the natural law of human reason, not merely a violation of Catholic theology. Therefore, Myers and George argued, Catholic politicians and voters were wrong to write off the church’s teachings as a matter of personal faith. What’s more, the letter warned, voting for a candidate or a law upholding abortion rights would almost invariably put a Catholic so far outside church teachings that he should not receive communion. As the first systematic rebuttal to Mario Cuomo and other Catholic politicians who support abortion rights, the letter kicked off a now-familiar debate inside the church. “Whenever I venture out into the public square, I would almost invariably check it out with Robby first,” Myers, now the archbishop of Newark, told me. Many of the bishops, Myers says, rely on George as “a touchstone” and “the pre-eminent Catholic intellectual.”

Last spring, George was invited to address an audience that included many bishops at a conference in Washington. He told them with typical bluntness that they should stop talking so much about the many policy issues they have taken up in the name of social justice. They should concentrate their authority on “the moral social” issues like abortion, embryonic stem-cell research and same-sex marriage, where, he argued, the natural law and Gospel principles were clear. To be sure, he said, he had no objections to bishops’ “making utter nuisances of themselves” about poverty and injustice, like the Old Testament prophets, as long as they did not advocate specific remedies. They should stop lobbying for detailed economic policies like progressive tax rates, higher minimum wage and, presumably, the expansion of health care — “matters of public policy upon which Gospel principles by themselves do not resolve differences of opinion among reasonable and well-informed people of good will,” as George put it.

A few months later, in a July 17 letter to Congress, the bishops did something close to that in the health care debate. Setting aside decades of calls for universal coverage, the bishops pledged to fight any bill that failed to block the use of federal subsidies for insurance covering abortion. “Stalin famously asked, ‘How many divisions has the pope?’ ” George wrote to me in an e-mail message after House Speaker Nancy Pelosi allowed a vote on an amendment that satisfied the bishops’ demands. “I guess Pelosi now knows.”

Check out the rest.