This was the intent of the Charleston Convention and why the RAT party was split and ran three candidates. Nevins history of the Rise of Lincoln goes into it as well as describes the treachery within Buchanan's cabinet on the part of the two of his officers.
Luis Gonzales might have a link to more about that. It was part of a long-standing conspiracy to split the Union.
If you have name of a book or paper about the conspiracy - I am interested. I have studied Catton's work about the candidates....Breck, Davis, Douglas. Rhett hammered away at the Mercury, I can't remember who Yancy was stumping for (perhaps himself).