Can you cite some pre-war quotes which predict what you claim here?
You may have never heard that some Southerners were concerned about candidate Lincoln's fidelity to the U.S. Constitution, but Lincoln himself acknowledged the concerns in the third sentence of his first inaugural address:
“Apprehension seems to exist among the people of the Southern States that by the accession of a Republican Administration their property and their peace and personal security are to be endangered.”
Later in the address, the President reassured the South that he would enforce the pro-slavery provisions of the United States Constitution.
Despite those apparently good-faith assurances, many people today argue the Great Emancipator actually “ fought to free the slaves.”