In his lecture on the current crisis in the Roman Magisterium, the full text of which, sadly, is not available, Fr Aidan Nichols justly oberved that the moral 'teaching' of Amoris laetitia, if not corrected, will "increasingly be regarded as at the very least an acceptable theological opinion. And that will do more damage than can easily be repaired".
In fact, the currently dominant tendenz has made no secret that this is precisely the plan: a plot to poison the very wells of magisterial teaching. As Archbishop Fernandez has publicly put it, "There's no turning back. If and when Francis is no longer pope, his legacy will remain strong. For example, the pope is convinced that the things he has already written or said cannot be condemned as an error. Therefore in the future anybody can repeat those things without being sanctioned".
There have been heretical popes in the past, but I doubt if there has often been a pope who (according to one of his closest collaborators and admirers) has cunningly plotted to enable heterodox teaching to erupt and flourish under his successor(s); and thus to undermine in advance the teaching of future popes. Strangling renascent orthodoxy before it has the chance to be born, if you will forgive my descent into rhetoric.
Did even Pope Honorius I dare to attempt that?