But each also carries something that makes it unlikely they will ever be elected pope -- a U.S. passport.
"If an American were elected pope, in the Third World the reaction would be that the CIA must have fixed the election or that Wall Street bought the election," said the Rev. Tom Reese, editor of the Jesuit magazine America.
"The Catholic Church doesn't need that kind of baggage."
Nearly all church observers say it is a near certainty that an American won't be elected pope in this conclave, or any other. But that doesn't mean American cardinals won't play an important role in deciding who will be elected.
There are 13 Americans in the College of Cardinals, but two are older than 80 and thus ineligible to vote. Of the 11 young enough to vote in the conclave for the next pope, seven head archdioceses, three hold posts in Rome, and one is semi-retired.
These American princes of the church range from Roger Mahony, the media-savvy progressive from Los Angeles, to Edward Egan, a hard-line conservative from New York. In the middle are the pastoral Theodore McCarrick of Washington, ecumenically minded William Keeler of Baltimore and soft-spoken Adam Maida of Detroit.
There's also scandal-scarred Bernard Law, the former archbishop of Boston who now holds a ceremonial post in Rome, and the intellectual Francis George of Chicago, who often tops the list of Americans who would be contenders for the papacy if only they weren't American.
Most experts say it is America's oversized role as the world's lone superpower that takes the U.S. cardinals out of the running -- especially in a post-Sept. 11 world where Washington has launched a global assault on terrorism.
"The pope has to be a figure who transcends politics if he is to possess any kind of moral credibility on the world stage," said the Rev. Richard McBrien of the University of Notre Dame.
There is also lingering suspicion of American Catholics within the Curia, the central Vatican bureaucracy that often has little patience with Americans' democratic -- and sometimes rebellious -- instincts.
"There's a view among many that American Catholics are liberals more concerned with altar girls and liturgical innovation than the life and death human rights issues that are so vital to the vast majority of Catholics in the rest of the world," said David Gibson, a veteran religion writer and author of "The Coming Catholic Church."
Still, as in most global affairs, the Americans may have outsized influence. Americans represent just 6 percent of the world's Catholics, but hold 10 percent of the seats in the conclave; Latin America, on the other hand, has 45 percent of the population but only 20 percent of the conclave.
Some candidates who may not be electable but will no doubt have great influence include:
-- McCarrick, of Washington, who is well-traveled, multilingual and widely respected for his approachable nature.
-- Mahony, of Los Angeles, who has strong ties to prelates in Latin America.
-- Justin Rigali, of Philadelphia, who is a veteran of the Curia and could call in favors from his time in a key Vatican body that appoints bishops.
-- George, of Chicago, a respected intellectual who served as global director of his religious order in Rome.
-- Law, of Boston, who despite his role in the clergy sex abuse scandal was Pope John Paul II's closest ally in America and remains an influential voice inside the Vatican.
Whomever is elected, Reese said, the next pope must win the favor of American cardinals, who will remain an important Catholic voice on the world stage.
"The last kind of pope they need is a guy who is going to say that a woman's place is in the home, that Jews control too much money, and that Protestants should come home to Rome," Reese said. "That would be a disaster in the American church."