Doesn't the SSPX oppose sedevacantism?
The Holy Spirit safeguards the Magisterium when they adhere to and practice the Faith of two millenia.
The Spirit safeguards the Magisterium precisely so it will adhere to the Faith! As for your appeal to free will, I counter with Augustine: "Almighty God is able to turn to belief wills that are perverse and opposed to faith ... the Almighty sets in motion even in the innermost hearts of men the movement of their will, so that He does through their agency whatsoever He wishes to perform through them" (On Grace and Free Will 29, 45).
The first condition of salvation is to maintain the rule of the true faith. 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. (Council of Constantinople IV, Profession of Faith)
Wrong.
Did the Holy Spirit safeguard Mahony when he wrote an heretical document claiming the Eucharist is present in the assembly? Even Mother Angelica had a problem with it. How about when he ruled there was no liturgical abuse going on in his diocese despite PICTURES to the contrary?
Was the Holy Spirit present when Mahony built his pagan temple complete with an inverted pentagram roof, a snake winding through the children's garden and sheep dogs about to attack the sheep?
Is the Holy Spirit present every time Kasper opens his mouth to utter yet another heretical statement?
Was the Holy Spirit present when the Pope kissed the Koran, a book which commands our slaughter as infidels?
Was the Holy Spirit present when the Magisterium claimed the Jews no longer need convert to be saved?
Do you call all of the above adherence to the Catholic Faith?
pascendi is right. You make a great case for sedevacantism.
Nice try. But the citation is a pious statement only, not always true. Many popes fell into material heresy, about forty, according to Vatican I.