I don't know what gets into you folks, who think you have some kind of argument to make here, when the truth of the 13th, 14th & 15th amendments should be plenty enough proof that's ridiculous.
The facts are that Lincoln during the Civil War did first what he constitutionally could do, which is emancipate slaves in states then in rebellion against the United States.
At the same time Republicans in congress debated various proposals for nationwide abolition, proposals which ended up as the 13th, 14th & 15th amendments.
And yet you people want to twist that all around, making it sound like Republicans didn't really care about emancipation, but the fact is they did, and also unlike Democrats then & now, Republicans cared about the US Constitution.
So what exactly is your problem with that?
You and I disagree and that's fine. You feel Lincoln's War, which killed about 600,000 Americans, was a necessary first step to passing the 13th, 14th, and 15th amendments in late 1865.
My belief is that the U.S. should have passed the three amendments in 1861 and that the war and all the killings should have been skipped.
To the larger point of the story - many conservatives today want to play the slavery/race cards in political debates because they resent the success that the Democrat party has had playing the slavery/race cards. That strategy is doomed to fail if wrapped in the mantle of Lincoln - because he was a very vocal white supremacist, a fact that is generally known.