"Senator Lindsey Graham...referr[ed] to his state’s difficulty in 'getting over' President Abraham Lincoln, with apparent reference to Lincoln’s role in the civil war and the freeing of American slaves."
I'm going to guess here that the Senator isn't mad that Lincoln freed the slaves, but that he completely devastated the South in doing it. Don't forget that Sherman's basic war strategy was to burn down any building standing south of the Mason-Dixon line.
The sustenance supplied to the armies of the south was in large part agricultural products. Destroy that produce and you shorten the war by depriving those armies of the means of existence. Shortening the war saved lives.
This was after years of pussy-footing around by Democrat General George McClellan. Look, if you want to commit treason against the USA, you're going to pay the price. As simple as that.
Yea and Sherman's strategy was pure genius. He lost very few troops.