Lee did have a chance to be president of the Confederacy during the war. A delegation of congressmen decided what they needed was not just a president but a dictator, and the best guy to be a dictator they could think of was Lee. So they approached him with the offer. He was so appalled he practically threw them out of his tent. As it happened, if he had been Napoleonically inclined, he had a fine army that was completely loyal to him and he could have done just such a thing. The very idea of that kind of power in his own personal hands was just too much for him! As so often happens in the CW, things often were mirrored by the opposite side. After his victorious march and the assassination of Lincoln, the Army of the Tennessee was camped outside Washington. No general was better placed to stage a coup than Sherman - and there were those who thought a dictator was just what the country needed. Sherman actually toyed with the idea and dismissed it! I don't think any of the generals wanted that much power. (Well, maybe Sickles!)