Could the next pope come from the United States?

The church has tried to keep the papacy separate from a reigning superpower for centuries, whether the Holy Roman Empire, France or Spain, according to the Rev. Thomas Reese, author of "Inside the Vatican: The Politics and Organization of the Catholic Church." When France captured the papacy, the nation moved the seat to Avignon in 1309 and kept it there for seven decades.

But the role of the United States in the world today is what weighs most heavily against a American pope. The Vatican navigates complex diplomatic relations within the Muslim world, in China over the state-backed church, in the Israeli-Palestinian conflict and beyond. An American pope could be perceived as acting in the interests of the United States instead of Catholics.

"That would be enough of a concern for enough cardinals to make them leery about voting for an otherwise good American candidate," Hilken said. "These men come from places. They're citizens of other countries of the world."

Despite all these factors, Dolan is being mentioned in some church circles as a potential — albeit longshot — choice. Round and quick to joke about his size, he is an ebullient and approachable representative of the church who is a strong speaker and is known in Rome. "He's the bear-hug bishop," Bellitto said.

Dolan already was part of one upset election: In a surprise 2010 vote, his fellow church leaders chose him over the expected victor as president of the U.S. Conference of Catholic Bishops. It was the first time in the history of the conference that the man serving as sitting vice president was on the ballot for president and lost.