When I was a kid .... whenever they were discussing the crisis with my parents or other trads, they used to say: "He who eats the pope dies," or variations of it. I know Fr. Ward knew of it, heck, I think even the then Fr. Sanborn knew of it.

Anyone else ever heard of it? 

AI Overview
The Catholic saying "who eats the Pope, will perish" (or "who eats the Pope, dies") means that the papacy is indestructible, because any enemy that attacks the pope would perish, that is to say, his actions against the papal institution would be doomed to failure. This expression is an affirmation of the durability of the Catholic Church, which will survive all those who seek to destroy it, even by attacking the figure of the Pope.

Origin and meaning

    The expression is a variation of the phrase of the French statesman Adolphe Thiers, "Qui mange le pape, en crève.", and which is taken up in Catholic circles.
    It expresses the idea that the papacy is a strong and perennial institution, which cannot be destroyed by external attacks.
    It shows that the Catholic Church will survive the loss of its temporal powers or other threats.

Example of use
The saying is a way of saying that the Catholic Church is eternal and that those who oppose it never succeed in making it disappear, even if they try to attack the Pope.