General

https://thecatholictrumpet.com/

A true pope cannot fall into heresy.  This is the First Opinion of the Five Opinions expounded on by St. Robert Bellarmine.

https://www.knightsrepublic.com/single-post/a-manifest-heretic-can-neither-become-nor-remain-a-pope

https://nonvenipacem.org/2024/09/03/feast-of-pope-st-pius-x-what-a-real-pope-sounds-like-2/