Unfortunately, the Resistance in general continues accepting Jorge Bergoglio as pope despite the sufficient evidence that he is not Catholic due to his public sin of manifest formal heresy.  This is not the position of Archbishop Lefebvre, who based his judgment on the evidence.  Today, it is Archbishop Vigano that most closely resembles Archbishop Lefebvre on this matter.

Unfortunately he seems to be leaning towards the position that the Apostolic See is vacant.

"Leaning"?  He's stated it unequivocally.

Nope. Bishop Thomas Aquinas gives the reason Archbishop Lefebvre rejected (even a 20-30 year) vacancy in the Papacy, which applies with even greater force to a 60-70 year one. Did you read it. Let me quote it: "His arguments are simple. What becomes of the Church if the Popes from John XXIII to Francis were never Popes? Were the Cardinals appointed by them not valid Cardinals? Who will elect the next Pope? How can we ever have a Pope again? Sedevacantism would seem to imperil the very existence of the Church."

I will give Bishop Vigano credit for one thing, he very clearly affirms what the earliest Sedevacantists also did - invalid Pope, invalid Cardinals, period. Some modern Sedevacantists, feeling too clearly the force of the objection presented by +ABL above, have vainly tried to pretend that somehow even a heretical or invalid Pope could install valid Cardinals, which contradicts cuм Ex and Catholic Theology. The stakes are clear: either the Popes of the last 66 years have been invalid Popes, and with them fall all Cardinals (and Diocesan Bishops), or they were valid. Tertiam non datur. (there is no third option here). Vigano said: "As I stated in my Communiqué of June 20, I do not recognize the authority of the tribunal that claims to judge me, nor of its Prefect, nor of the one who appointed him." https://insidethevatican.com/news/newsflash/letter-22-2024-friday-june-28-vigano-statement/

This opinion, although for now Vigano applies it only to Pope Francis, flatly falls under the objection raised by Archbishop Lefebvre. Soon enough, he will recognize it is a dead end, as millions have realized in 60+ years. Let me quote +ABL: https://www.sspxasia.com/Docuмents/Archbishop-Lefebvre/Apologia/Vol_two/Chapter_40.htm

Quote

"They argue further that, chosen by a heretical Pope, the great majority of the cardinals are not cardinals at all and thus lacked the authority to elect another Pope. Pope John Paul I and Pope John Paul II were thus, they say, illegitimately elected. They continue that it is inadmissible to pray for a pope who is not Pope or to have any "conversations" (like mine of November 1978) with one who has no right to the Chair of Peter ... Does not the exclusion of the cardinals of over eighty years of ages, and the secret meetings which preceded and prepared the last two Conclaves, render them invalid? Invalid: no, that is saying too much. Doubtful at the time: perhaps. But in any case, the subsequent unanimous acceptance of the election by the Cardinals and the Roman clergy suffices to validate it. That is the teaching of the theologians.
The visibility of the Church is too necessary to its existence for it to be possible that God would allow that visibility to disappear for decades. The reasoning of those who deny that we have a Pope puts the Church in an inextricable situation. Who will tell us who the future Pope is to be? How, as there are no Cardinals, is he to be chosen? This spirit is a schismatical one for at least the majority of those who attach themselves to certainly schismatical sects like Palmar de Troya, the Eglise Latine de Toulouse, and others."

Well said. The quote from +ABL above shows that he would not have been a sedevacantist now. It has been mentioned on this thread that +ABL followed the evidence, when actually, what he prudently followed was the teachings of the Catholic Church. 

Well said. The quote from +ABL above shows that he would not have been a sedevacantist now.

No, it really doesn't.  It's well known that during the early 1980s, +Lefebvre was more hopeful and got into +Fellay mode, where he was seeking a practical arrangement with Rome, i.e. being allowed to make the "experiment of Tradition" within the Conciliar pantheon.  But by the time of Assisi, after his hope for Wojtyla had faded, he stated that if Assisi were to take place (it did, obviously), he might have to declare the See vacant.  So +Lefebvre seem to respond to events in going back and forth on matter, and he could easily have rejected Bergoglio who in many ways makes Wojyla look like St. Pius X by comparison.  Now, whether he would have become a Bennyvacantist or straight SV is hard to know, but in any case this line of thinking is utterly idiotic, showing that far too many engage in +Lefebevbre personality-cult worship.  +Lefebvre was wrong about quite a few things, including the consecration of +Fellay, but by no means was he infallible or some kind of rule of faith, a prerogative that belongs to the Papal Magisterium and which the R&R types have somehow transferred instead to +Lefebvre.  This is in keeping with Bishop Williamson's itching ears, always seeking out and being excessively credulous of private revelation.  +Williamson saw +Lefebvre as some kind of divine oracle and therefore rule of faith.  While it's complicated by the fact that +Lefebvre has been gone for over 3 decades now, it's a non-Catholic mindset to uphold a fallible man as a rule of faith while at the same time refusing that prerogative to the Papal Magisterium, where it rightly belongs.

Well, he was citing Bishop Tomas Aquinas.

You're right. Though maybe he was judging it by the fact that "real" sedevacantists believe that all the conciliar popes have all been invalid.

Are there any heresies committed by Francis that weren't also committed by JP2? +ABL certainly believed that JP2 was a real Pope, though a modernist.

The difference is that Jorge Bergoglio has shown himself to be pertinacious.