Abolition of slavery required bribery and political coercion, not just moral persuasion

Evidence

The president faced formidable challenges. Much of the public was unsympathetic to the initiative. His own party was deeply divided on the issue, which threatened to prolong the horrendous Civil War. Lincoln was a resolute moralist on the core principle of racial equality but a pragma-tist on the means to achieve it. He used his considerable influence, along with the forceful political maneuvering of Thaddeus Stevens, a powerful House member, to sway reluctant congressmen. The maneuvering included arm-twisting, promises of patronage jobs, and even political bribery. … In his review of the movie Lincoln commenting on these coercive tactics, A. O. Scott (2012) noted, “The better angels of our nature sometimes need earthly inducements to emerge.” — Albert Bandura, Moral Disengagement, 122