It is a Catholic dogma that the Apostolic See of Rome will always "hold out". Per the IVth Council of Constantinople:
We have to define what "holding out" is. That can't possibly mean papal impeccability. Right?
The first condition of salvation is to maintain the rule of the true faith.
Popes individually are not guaranteed salvation personally, correct? So, that would leave open the possibility of a Pope not maintaining the rule of faith in his person. Correct?
And since that saying of our lord Jesus Christ, You are Peter, and upon this rock I will build my Church, cannot fail of its effect, the words spoken are confirmed by their consequences. For in the Apostolic See the Catholic religion has always been preserved unblemished, and sacred doctrine been held in honor.
This then, begs the question: Just how bad can a Pope be? Where is the defined impossibility that the Apostolic See can't engage in? Once we find that untouchable place, everywhere before that point is possible.
I asked one of the SSPX apologists here about this and he told me that the Council was wrong, and said the same about Pope Sixtus IV's condemnation of "the Church of the City of Rome can err" as being "contrary to the holy Catholic faith" and as containing "manifest heresy" (Bull "Licet ea", Aug. 9, 1479). Go figure.
Was he a card-carrying member of the SSPX apologist's task force?
That can't possibly mean papal impeccability. Right?
I don't think anyone has ever claimed that Popes are made sinless in virtue of their office.
So, that would leave open the possibility of a Pope not maintaining the rule of faith in his person.
I disagree and I refer you to Bellarmine's judgment about the impossibility of a heretical pope. In any case it is irrelevant since what we are discussing here is whether it could happen that the Roman Church cease to be Catholic, not whether the Pope could fall from his see, as would happen if he became a heretic.
Once we find that untouchable place, everywhere before that point is possible.
"For in the Apostolic See the Catholic religion has always been preserved unblemished, and sacred doctrine been held in honor". Looks like a sufficient guarantee to me that the Catholic religion will never end up having to be based out of Econe. Of course, many in the SSPX don't see it that way.
What remains of the magisterium in the Church? ... Well, this magisterium, at least as regards the truths denied by the conciliar hierarchy, lies in Mgr Lefebvre in whom it can be found in a certain manner. He is the veritable echo of tradition, the faithful witness, the good shepherd whom simple sheep have been able to identify from the wolves in sheep’s clothing. Yes, the Church still has a living and perpetual magisterium and Mgr Lefebvre is its saviour. The indefectibility of the Church can be seen in the inflexibility of the Archbishop. (Bernard Tissier de Mallerais, Fideliter, n. 72 (1989), p. 10)
Was he a card-carrying member of the SSPX apologist's task force?
Not that I know of. Are you? :)