According to U.S. News and World Report, the most important Roman Catholic figure in President Obama’s administration is someone whom few Catholics would recognize.

Mark Linton, the director of Faith-Based and Neighborhood Partnerships at the Department of Housing and Urban Development, is the White House’s top Catholic liaison. He not only prepared the president for his first meeting with Pope Benedict XVI, but also helped the president reach out to American Catholics prior to the visit.

A former employee of Catholic Relief Services, Linton worked as a legislative assistant in Obama’s Senate office before heading up Catholic outreach for Obama’s presidential campaign in 2008.

“Mark has access all the way up the chain of command at the White House and has delivered a great level of access,” a Catholic social justice activist who requested anonymity told U.S. News.

In advance of the meeting between Obama and the Pope, Linton’s duties ranged from mapping out Benedict’s thinking on key issues for Obama to determining the gift that the president presented to the Pope. Linton enlisted Catholic theologians and Church experts from around the country to help with the job.

“I wanted them to understand the nature of the Pope’s thought, especially because Obama has written on hope and so has Benedict,” says Vincent Miller, a University of Dayton theologian debriefed by Linton. “One area we talked a lot about is Benedict’s concern with truth, which translates ... to something that is similar to Obama’s interest in a reconceived politics that face issues deeply, in long, detailed speeches.”

Many of Linton’s phone calls to American Catholic leaders last week focused on how the president could use the encyclical Pope Benedict released last Tuesday, Caritas in Veritate (Charity in Truth), revolving largely around the global economic crisis, to launch a discussion of common goals.

Other theologians whom Linton talked to stressed the need to be prepared for the Pope to bring up areas of disagreement with Obama on social issues like abortion and embryonic stem-cell research. “I’m very confident that the White House was prepared to talk about that,” said Stephen Schneck, director of The Catholic University of America’s Life Cycle Institute, who spoke with Linton last week.

Schneck said the White House was prepared to promote what it has called a “common ground” approach to reduce the need for abortion without restricting abortion rights.

Linton has also been key to earlier White House decisions affecting Catholics, including the recent appointment of Miguel Diaz as ambassador to the Vatican. The nomination was a surprise because Diaz is a Catholic theologian who is largely unknown in the political world. His conservative record on abortion avoided inciting the kind of opposition that would have accompanied the appointment of a pro-abortion-rights Catholic Democrat.