Gibson, of Fordham, said another factor that might throw off the traditional resistance to an American pope is the election of President Donald Trump. Some cardinals might want a pope from the United States to confront Trump on issues such as immigration and aid for the poor.

The papal conclave—the election of the next Pope—is set to begin on May 7, and will see 133 cardinals gather to vote.

Cardinals will on Tuesday begin moving into the Vatican accommodation where they will stay during the conclave, on the eve of their historic, secretive meeting to elect a new pope. Following the death of Pope Francis on April 21,