Most sedevacantists claim that the last pope was Pius XII and that Pope John XXIII (Cardinal Roncalli) was invalidly elected because he was a heretic prior to claiming the papal throne. But according to the Ecclesiastical Law, in order for Cardinal Roncalli’s election to the papacy to have been invalidated for heresy, Pope Pius XII would have had to judge that Cardinal Roncalli was a heretic, since Pius XII is sole judge of his Cardinals under canons 1557 and 1558 of the 1917 Code of Canon Law. But he did not.

Quote from: 2Vermont

Quote from: Cantarella

Most sedevacantists claim that the last pope was Pius XII and that Pope John XXIII (Cardinal Roncalli) was invalidly elected because he was a heretic prior to claiming the papal throne. But according to the Ecclesiastical Law, in order for Cardinal Roncalli’s election to the papacy to have been invalidated for heresy, Pope Pius XII would have had to judge that Cardinal Roncalli was a heretic, since Pius XII is sole judge of his Cardinals under canons 1557 and 1558 of the 1917 Code of Canon Law. But he did not.

I'm *shocked* that Cantarella chimed in here with a post against the SV position despite the OP's request:

I respectfully ask non-sede's (like myself) not to hijack this thread into an argument about the merits of sedevacantism or to attack sedevacantists

Cantarella is anti-SV first, then Catholic.