Lincoln said he wanted slavery to be safe, rare, and legal.
What he actually wanted is anyone’s guess. He said enough stuff on the record to prove anything.
Many southerners felt Lincoln, if elected, would look for a pretext to attack and destroy the south. For some reason they did not want this to happen.
I can cite any number of quotes in which he says he had no intention or authority to interfere with slavery. I’ve cited quotes that show he was willing to offer strengthened federal fugitive slave laws. He publicly supported the Corwin amendment. Nobody was under any illusions about him attacking the South or slavery had the Southern states remained in.
“Nobody was under any illusions about him attacking the South or slavery had the Southern states remained in.”
The South was in the union in 1859 but they were attacked by John Brown in a murder raid financed by prominent northerners. The financial backers were given sanctuary by politicians in the north.
The South was in the union in 1860 but they were attacked by northern business and political interests in the form of confiscatory taxation - with higher rates promised by regional candidate for president A. Lincoln.
And in his “House Divided” speech, Lincoln had said slavery would end by hook or by crook. Southerners were alarmed by his reckless disregard for the benefit of the bargain provided for in the constitution.
It is true slavery could not be legally abolished by the North through constitutional amendment without southern support. What southerners feared going forward, and rightly so, was extra-constitutional methods, including economic warfare and violence.