It is important to remember that Bellarmine did not teach that a manifest heretic was ipso facto excommunicated *latae sententiae*, but both Bellarmine and Suarez taught that the ipso facto loss of office occurs after the Church judges the Pope to be a manifest heretic. https://twitter.com/ColleenEldrach1/status/1311787148543229952

"Therefore on deposing a heretical Pope, the Church would not act as superior to him, but juridically and by the consent of Christ she would declare him a heretic and therefore unworthy of Pontifical honors; he would THEN ipso facto and immediately be deposed by Christ…” -Suarez

By reading the second and third opinions, it is evident that Bellarmine agreed w/ Suarez.

“A Pope can be judged and deposed by the Church in the case of heresy; as is clear from Dist. 40, can. Si Papa: therefore, the Pontiff is subject to human judgment, at least in some case."

The second opinion is actually the one supported by sedevacantists, though they don't realize this. The second opinion holds that the loss of office occurs with violation of divine law without the need to be judged by the Church. Bellarmine's rebuttal of the second opinion is...

...very similar to Suarez' position, that being that God doesn't make a man Pope without the affirmation of men, neither will Christ depose the Pope "unless it is through men." It would be done "juridically and by the consent of Christ."

The third opinion need not be covered much, but Bellarmine refutes the idea that a Pope cannot be judged and establishes that they can. Bellarmine defends the notion a Pope can be deposed by making it clear that they can be judged by men in the case of heresy.

The sedevacantist interpretation of "...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 a member of the body of the Church; whereby he can be judged and punished by the Church" is false.

An ipso facto loss of office does not occur like an ipso facto latae sententiæ excommunication. A heretical pope can be judged, and can be removed by God through men. The sedevacantist appropriation of Saint Robert Bellarmine is not just flawed, it is completely false.

Bellarmine on the other handed actually defends the R&R position in his work. "I say that it is lawful to resist [the Pope] by not doing what he orders and preventing his will from being executed."

Context: a valid Pope acting against the Catholic faith and the Church.