[Mrs. Don-o]

"Heretic pope is a contradiction in terms. If he is a manifest heretic then he loses membership in the Catholic Church and therefore, not Pope."

I am not sure that is so. Being bishop, like being priest, inscribes an indelible mark on the soul, and what person or organization can you name which can depose the Bishop of Rome?

Bingo

[sitetest]

The pope would remain a bishop, but if a heretic, would nonetheless lose communion with the Catholic Church and cease to be pope.

But only the College of Cardinals could pronounce him formally a heretic, or a successor pope.

At best, we laymen can note that a pope seems to be in heresy, but we have no authority to actively act on that conclusion.

[tioga]

My 93yo Catholic MIL swears to that. She is not worried in the least about him.

[RobbyS]

What has happened,o course, is the choosing of anti-popes. A great scandal, but it could happen again.

[onedoug]

...and what person or organization can you name which can depose the Bishop of Rome?

islamists.

[piusv]

Now the fifth true opinion, is that a Pope who is a manifest heretic, ceases in himself to be Pope and head, just as he ceases in himself to be a Christian and member of the body of the Church: whereby, he can be judged and punished by the Church. - St Robert Bellarmine

The manifest heretic pope automatically ceases to be pope, Catholic and member of the Church. Subsequently the Church declares it.