Sedevacantism is the only answer to the question. If sedevacantism is not true and these herertics are popes, then answer the question, "Can Catholics ever trust the pope to be their teacher and lawgiver?"
If the Pope cannot be trusted it will be the right and duty of Catholics from now until the end of the world to distrust popes, because if we cannot trust Benedict XVI, John Paul II, and Paul VI, then the principle will always be that popes are not protected by God and can lead Catholics to Hell.
Is that what you want to call the Catholic Church?
Archbishop Lefebvre, in no uncertain terms, classified Cardinal Ratzinger, John Paul II and Paul VI as heretics... even worse as modernists! (Modernism was labelled by Pope St. Pius X as "the synthesis of all heresies".)
With Benedict XVI we have a first in the history of the Church. A claimaint to the Papacy "ordained" Bishop in Bugnini's dubious rite.
Joseph Ratzinger- 29 Jun 1951 Ordained Priest
- 28 May 1977 "Ordained" Bishop (Bugnini Rite)
A couple of questions. 1. Was he conditionally Consecrated in the traditional Rite?
2. Can a man (setting aside for a moment that he is a manifest heretic) be Pope without being a Bishop?
FYI. Not claiming to have the answers, just a few questions.