And we're not in that situation now, either. As lousy a Pope as Francis is, he is not a formal heretic. Pope Pius X in his Constitution "Vacante Sede Apostolica" says: "By reason or pretext of any kind of excommunication, suspension, or interdict or any other ecclesiastical impediment, no Cardinal can be excluded, in any manner, from an active or passive (papal) election”. Again the same is affirmed by Pope Pius XII in "Vacantis Apostolicae Sedis" (AAS 38 [1946], p. 76).
For Bishops and Cardinals to be canonically declared as "heretics" in the first place, it would have had to have been declared by the Pope alone (Canon 1557 & 1558). But this was not the case for Bishops Roncalli, Montini and Wytola. As destructive as their actions were to the true Church, we cannot claim that they are formal heretics based on our private judgment in the matter, anymore than Martin Luther had the right to nail his 91 Theses to the door of Wittenbrug Church. We simply don't have that privilege, however strongly we may feel on the matter.
The Papacy belongs to the Catholic Church, not to the V-2 sect
The Catholic Church as the Sedevacantists in their private sovereign authority define it, evidently.
Some people in trying to be true to Christ are confused and in attempting to be loyal to Him and His Church, falsely equate it with the V-2 sect and blindly accept any atrocity that emanates from it.
To the contrary, many faithful Catholics vehemently reject the doctrinal and spiritual falsehoods produced under recent Popes; but it does not follow that theyshould therefore declare the Papacy of an erring Pontiff null and void. In the words of St. Robert Bellarmine, "Just as it as it is licit to resist the [Roman] Pontiff who attacks the body, so also it is licit to resist him who attacks souls, or who disturbs civil order, or, above all, him who tries to destroy the Church. I say that it is licit to resist him by not doing what he orders and by impeding the execution of his will; it is not licit, however, to judge, punish or depose him, since these are acts proper to a superior."
“In the words of St. Robert Bellarmine, “Just as it as it is licit to resist the [Roman] Pontiff who attacks the body, so also it is licit to resist him who attacks souls, or who disturbs civil order, or, above all, him who tries to destroy the Church. I say that it is licit to resist him by not doing what he orders and by impeding the execution of his will; it is not licit, however, to judge, punish or depose him, since these are acts proper to a superior.””
Sorry, this does not condemn sedevacantism.
http://www.traditionalmass.org/articles/article.php?id=25
Not a novelty, eh?