The election of a new Pope is a drawn out and contentious affair, but it seems that the selection of a new Pope is not always as difficult as it needs to be.
Take the instance of the election of Pope Fabian back in 236AD. He was hardly seen as being a contender for the position and was not really taking part in the process, or as little as he could afford to do, but that all changed in an instant.
During the deliberations, a dove is said to have landed on his head as they debated the election of a new Pope. In an instant he was taken from not even being considered, to being made the new Pope.
Why? Well, the others that were present saw the dove landing on his head as a sign that the Holy Spirit had decided that he was to be the new Pope, and who were they to go ahead and argue against that? It turned out that he was then elected Pope and served until his death in 250AD.