[Bubba Ho-Tep]

This doesn't even address what would have happened had Lincoln been successful in passing the Corwin amendment. If that effort had worked, slavery would have continued indefinitely.

Let me see if I understand your argument here. Slavery could never be abolished because it would require too many states to ratify an amendment than would ever pass it, but if the Corwin Amendment had passed...slavery could never be abolished. Is that about right?

[DiogenesLamp]

Let me see if I understand your argument here. Slavery could never be abolished because it would require too many states to ratify an amendment than would ever pass it, but if the Corwin Amendment had passed...slavery could never be abolished. Is that about right?

Pretty close, however at this point I have to put in a qualifier.

Slavery could be abolished by existing slave states giving it up voluntarily. (Which I think would have happened eventually anyways.) Without the Corwin amendment, eventually enough would have done so to ban it in the rest. With the Corwin amendment it would have remained so long as any single state wanted it.

Other than that, yeah, all else being stable, pretty much permanent.