[central_va]

The fact is the constitution did not apply to any such contingency as the one existing from 1861 to 1865. Its framers never dreamed of such a contingency occurring. If they had foreseen it, the probabilities are they would have sanctioned the right of a State or States to withdraw rather than that there should be war between brothers.

U. S. Grant

Seems pretty clear to me.

[Sherman Logan]

Well, no.

He is saying that the Founders would probably have allowed for a legal means of secession if they had foreseen the situation that arose in 1860.

But they didn’t foresee it, so made no such provisions.