Craig,
That is a good question. It is in the realm of "tricky" for sure. My own opinion is that if they had been able to do that before Vicksburg and Gettysburg, it might have caused Lincoln the 1864 election. I think after Vicksburg the handwriting was on the wall, the south was done as a country. I agreed with your contention in the earlier posting. It was well thought out in my opinion.
Lee would have had to have a very large force to pull it off. It seems to me that everytime he left Virgina he got beat. He tried it in Maryland and the Marylanders did not support his effort. He got very little support there. And at Gettysburg he did not pull it off either. I think that Longstreet tried to talk him out of that incursion with no success. To use a modern term, he would not have had the hearts and minds of the people.
To go back to the beginning of the war, Mr. Lincoln set a trap for Mr. Davis and Jeff walked right into it. If the north had been able to supply Ft. Sumpter, the south would have recoginzed the sovernty of the north. Since they fired on the fort based on Davis's orders, that gave the north the opportunity they needed to invade the south to restore Federal Authority. In my opinion. Before secession Lincoln only wanted to insure that slavery did not spread to the new territories. From what I read, he did not want to interfer with the way things were in the slave states.
Frank