Actually, you’re the one engaging in a bit of revisionist history…especially by omitting the fact Lincoln’s views on race and racial equality evolved to the point he came around later in his life.
To illustrate this, he wrote the following sometime in the 1850’s…well before he ran for office and became President:
http://quod.lib.umich.edu/l/lincoln/lincoln2/1:264?rgn=div1;view=fulltext
While taken for granted today by most reasonable people, the expression of racial equality above was extremely radical for the time even among some of the more mainstream “polite” abolitionists of the era.
From his own writings, one can understand why many White southerners…overwhelmingly conservative Southern Democrats of that era in particular STRONGLY SUSPECTED him of abolitionist sympathies and thus, felt the need to influence their respective states to secede from the union to preserve their “states rights” to own and maintain slaves as personal property and to have that right protected by laws which cover protection of other forms of personal property once he was elected president.