If sedevacantism is not binding on non-sedevacantists (as many sedes in this forum concede), how is it binding on the man who the sedes call Ratzinger?

Yeah I don't get it either.  

Sedevacantists have no power to bind someone against their will.  
We prefer to let people come to the truth without pressure.  But the "floating trads," as I think you call those who take no firm stand and fluctuate between SSPX, Vatican II and sede chapels, will still have to face God one day and give an account of themselves.  

For myself I would rather be a hardline sedevacantist as it is the only consistent position.  I think the other positions all have an element of lukewarmness and cowardice, of trying to cover one's bases, of -- flatly -- compromise.  But if someone in my chapel wants to duck out to SSPX one weekend, that's his affair.  What am I going to do, lasso him?  You can lead a horse to water but you can't make him drink.

I will say that the few people I know who are "floating trads" seem much more tormented internally, unstable in their faith, than the pure sedes.  People who become sedes have very high degrees of faith because of the peace of mind they have, the satisfaction of seeing the giant puzzle come together.  

That's right Gladius but we DO have proof.

We have the dogmas of infallibility and indefectibility.

Now, a Pope who teaches heresy is not infallible.  And a Church that goes along with his heresy is not indefectible.

Ergo, these are not real Popes and the spiritual brothel they run is not the Catholic Church.

2+2 still equals 4, and it feels so good.

What I'm trying to do is show that we can come to the sedevacantist position based purely on dogma, without need for special graces or insight.  Reason illumined by faith is nice, and that is how we probably both got here.  But what's even nicer is that our first educated hunch turned out to be backed up by cold hard fact.

I reiterate this because I don't want to make people think they have to leap off a cliff to be sedevacantist.  I want them to see that it is the only theologically coherent position to take in our time; that it is in fact the only way to maintain all the dogmas.

The question is how can we think, "I don't think he is the pope, but you validly can think that he is the pope" b/c that would lead to the position that he validly is and validly is not the pope simultaneously?  I'm just wanting to understand if this is what you are getting at.

The question that I'm getting at is the question of authority.

By what authority is the Pope himself removed from office? If the answer is that he removes himself by his heresy, then by what actual, here-and-now, living-and-breathing authority is his heresy and its consequences authoritatively declared?

But if someone in my chapel wants to duck out to SSPX one weekend, that's his affair.  What am I going to do, lasso him?  You can lead a horse to water but you can't make him drink.

Wait a sec- you would not admonish him for his mortal sin against the Faith?

You talk about the giant puzzle fitting together, but you are missing the BIGGEST piece Michael.  The salvation dogma.  The only way into the Church is baptism. The only way into the Church is baptism. The only way into the Church is baptism.  So saith the Lord.