The Sedevacantist side has its arguments, docuмents, quotes from the saints, private revelations.
The Recognize & Resist side has its arguments, docuмents, quotes from the saints, private revelations.
Both sides claim quite a following, though the SSPX (before it started dropping the "Resist" part) -- representing the R&R position -- was much larger.
At any rate, in the past FORTY-FIVE YEARS* neither side has managed to put together a convincing enough case to absorb the other side or reduce it to a small, stubborn, sect of bad-willed people.
It hasn't been for lack of trying! Every day, men on both sides come forward, trying to be the hero that will discover the Holy Grail of this Crisis buried deep inside some Patristic writing, Scripture, private revelation, Vatican archives, and/or the laws of Logic.
But it appears to me that the case is NOT open-and-shut as some would have us believe.
Which makes sense to me (and others). A crisis of this magnitude has never happened before. No, the Arian crisis wasn't this bad. No, the Great Schism wasn't either. Those crises were faint foreshadowings of our current Crisis. And as far as I know, Our Lord hasn't appeared to anyone to definitively rule on the Sede vs. R&R debate.
Since we still have these 2 sides, one explanation is that either the R&R side or the Sede side is filled with ignorant and/or bad-willed people. I reject that hypothesis.
Even if you restrict yourself to the well-educated and well-informed on both sides, I wouldn't be willing to admit that 100% of either side is bad-willed.
So we have this stalemate.
Apparently each side has some very powerful arguments, against which the other side hurls its arrows and countermeasures in vain. My conclusion: Each side is a "valid" response to this Crisis in the Church. It all depends on which dogma you're going to focus on.
I think it bothers each side that the other side exists -- the R&R Catholics feel like timid fence-sitters next to the Sedes, and the Sedes feel like imprudent or simplistic hotheads next to the R&Rs. They both have that little voice asking them, "Are you sure you're right?" so the more argumentative among them spend hours of their time every week (or even every day!) on polemics to try to crush the other side.
Both sides certainly have things to be embarrassed about in the past 45 years regarding their members, leaders, even the official policies of some of their adherents. I need not going into detail here. If you honestly aren't aware of these embarrassments, I can enlighten you.
But after 45 years, here we are.
* counting from 1969 -- this date is just picked out of thin air -- most Sedes say the interregnum began earlier than that. So replace 45 years with 52 years or whatever. If the number is greater, my post is just all the more true.