Replace Pope Benedict XVI with whom?

It falls to Tom Flynn (the executive director of the Council for Secular Humanism, for crying out loud) to raise the obvious question:

Sex abuse by Roman Catholic priests has emerged as a worldwide (or at least, First World-wide) phenomenon. It's no longer an American issue, nor an Irish issue. The fact that scandal has erupted in Europe and that the former Cardinal Ratzinger may have been involved in under-responding to it simply means that the problem is global, and within the church all lines of responsibility lead ultimately to the papal throne. Should Pope Benedict XVI be held responsible? Yes. Should he be investigated? Yes? Should he resign? Hold on, let's wait fo the investigation! But there's a bigger question here. If investigation reveals that Cardinal Ratzinger participated in covering up abuse in Europe, and if the pope resigns -- who could replace him? Across the world, a minority among Catholic priests apparently engages in sex abuse. Church hierarchs have pretty consistently responded by keeping it quiet, reassigning problem priests, sending them off for therapy but then sending them back to parishes. So if Pope Benedict needs to be replaced, where will Rome find a cardinal whom everyone can be certain has never played a role in mishandling an allegation of abuse?

Of course the other On Faith responders have differing views.

But where, indeed.