So the repeal of the Missouri Compromise opened that whole territory to the ingress of slavery. That sparked the greatest political revolution in American History. In the spring of 1854, when the Kansas-Nebraska Act was passed, there was no Republican Party; there were no Republican congressmen. In the four elections of 1854, 100 Republican Congressmen were returned to the Congress. At that moment, Stephen A. Douglas was looked upon as the antichrist from the point of view of the anti-slavery movement.

The Real Abraham Lincoln: A Debate (2002)