But the breadth of Catholic teaching does not fit comfortably with either major party. The church opposes abortion and embryonic stem cell research, as do most Republicans; but it stands against the death penalty and the war in Iraq, like most Democrats.
At the United Nations, where he spoke on human rights, Pope Benedict called for "a deeper search for ways of pre-empting and managing conflicts by exploring every possible diplomatic avenue, and giving attention and encouragement to even the faintest sign of dialogue or desire for reconciliation."
With Bush, the pope discussed what the Vatican and the White House described in a joint statement as "the need for a coordinated policy regarding immigration, especially their humane treatment and the well-being of their families." The leaders also "touched on the need to confront terrorism with appropriate means that respect the human person and his or her rights," according to the statement.
And during his homily yesterday at Yankee Stadium, Pope Benedict spoke of the "inalienable dignity and rights of each man, woman and child in our world - including the most defenseless of all human beings, the unborn child in the mother's womb."
Part of Pope Benedict's mission, as he made what might be his only papal visit to the United States, was to energize Catholics in their faith. At every stop, from the meeting with bishops in Washington to a rally for youth in New York, the soft-spoken former theology professor focused on encouragement.
For Sarah and Michael Gillman, Baltimoreans who attended the Mass at Nationals Park, the pope's appearance had the desired effect.
"It's such an amazing thing to be able to see the holy father in the United States," said Sarah Gillman, a medical student at the University of Maryland at Baltimore. "It's exciting just to be able to get together with so many Catholics, sharing the experience."
O'Brien called Pope Benedict's visit "a milestone for the Catholic Church in the United States." What lies ahead, he said, is a period of reflection.
"We're going to have to sort out all the messages and insights he has given us," O'Brien said. "It's going to take some time."
matthew.brown@baltsun.com