The Republicans inculcate, with whatever of ability they can, that the negro is a man; that his bondage is cruelly wrong, and that the field of his oppression ought not to be enlarged. The Democrats deny his manhood; deny, or dwarf to insignificance, the wrong of his bondage; so far as possible, crush all sympathy for him, and cultivate and excite hatred and disgust against him; compliment themselves as Union-savers for doing so; and call the indefinite outspreading of his bondage "a sacred right of self-government".

Speech on the Dred Scott Decision (1857)