A papal conclave blends the political and the spiritual, cardinals and theologians say. Here, in Catholic belief, is how the Holy Spirit fits in.

Cardinal Daniel DiNardo of the Archdiocese of Galveston-Houston says he wants the new pope to be "a man of unity for the Church."

Cardinals who will take part in the secret conclave to elect a new Catholic pope began checking into two Vatican hotels on Tuesday, where they will be barred from contact with the outside world as they decide who should succeed Pope Francis.