The man's health has deteriorated and perhaps he is going senile. I think perhaps the conclave of cardinals will see sense and vote for a younger applicant. It must be very hard for someone of the pope's age. Maybe a pope from the third world would bring some new blood into the papacy.
Do you apply for the Papacy? Seriously, how does it work? Do they all do a pitch in the conclave and the one with the most mates wins? Or do you rig some holy trick that tips your competitors out the barrow? Or is it all dirty politics?