Lincoln spent the entirety of his presidency killing the people he considered his citizens on a then-unprecedented scale. He was quite clear he didn't want to free the slaves, was actually a racist himself, and really only did the Emancipation Proclamation as a war tactic to keep Britain from funding the Confederacy- it did not apply to his own people. He also routinely trampled over the first amendment and had Confederacy sympathizers arrested. He would not be nearly as beloved if he hadn't been quickly assassinated after the war was over, and the US wasn't quite so desperate to convince itself the Civil War was totally worth the ridiculous levels of bloodshed.