>>no one could ever turn to Christ<<
By him or herself, no.
>>they are beyond all hope of grace, beyond all hope of the Spirit ever operating within them.<<
No, and you've made a large leap to try and connect the two thoughts. They are not beyond hope of the spirit operating in them, they are beyond hope of somehow generating faith all on their own - which is what Graham is suggesting. The point is, they cannot "choose" to seek Christ, unless God is pleased to reveal it to them.
>>How, pray, can a man turn from sin to God if not through grace?<<
I did not negate grace. I said that man cannot do it by his own power.
That is not at all what Graham is suggesting, and you are ending up agreeing with his position! He said that people in whom the Spirit is operating--may possibly be saved by responding to those operations, but always saved by and through Christ. He is not a Pelagian, and neither are we.
The point is, they cannot "choose" to seek Christ, unless God is pleased to reveal it to them.
And no one says otherwise...but who is anyone to say that God does not please to reveal it--in some way--to those who are outside the Church? Will you tie the hands of the Almighty now?
If someone responds to the graces they are given, the possibility of salvation is there: not through their own merits of course, but through the merits of Christ.
Don't forget, my friend, it's the Catholic Church who still hold tenaciously to the famous dogma "Outside of the Church there is no salvation". Properly interpreted of course. :)