Stephens promoted the idea of the perpetuation and expansion of the institution of slavery as a positive good.
Lincoln was elected on a platform of preventing its expansion with the eventual goal of its abolition due to its being a great evil.
If there was no difference between these two positions, why did the southern states feel compelled to secede to protect their peculiar institution when Lincoln was elected?
I’m still waiting for anybody to post contemporaneous southern disagreement with the Cornerstone Speech, which I contend received no such disagreement because it perfectly expressed the conventional wisdom in the South.
If the South was indeed moving towards eventual abolition, such disagreement shouldn’t be hard to find.
Good luck.
That bit of logical legerdemain would be impressive, if there were any truth to it.
Insofar as you ask for something or someone to "perfectly express the conventional wisdom in the South", see the following: here