Lincoln was no tyrant. Jefferson Davis was the tyrant. Praise and honor to brave Southerners like Lee and the typical reb soldier is one thing, but an attempt to bring Lincoln down to the sordid political level of the secessionists is taking Southern defensiveness and sore loser syndrome to an extreme level. Not only did Davis and his minions head a regime whose cornerstone was keeping an entire race in bondage, they also trampled on the rule of law and the rights of any white Southerners who did not sufficiently dance to the slaveowners' tune.
Slavery would have ended and was phasing out. Lincoln knew that. The war wasn't about slavery. It was suppressing an Revolution of Independence.