[T]he one unforgivable sin, according to dominant Southern public opinion, was moral condemnation of slavery. - Harry V. Jaffa

DiLorenzo thinks that it is a reflection on Lincoln's anti-slavery character that he supported the Fugitive Slave Act. But the Fugitive Slave Clause is in the Constitution, and Lincoln thought that any refusal to implement the right clearly defined in the Constitution would justify secession. You can't pick and choose which parts of the Constitution you like. Once you do that, then the Constitution is simply, as Jefferson said once, "a blank sheet of paper." Jefferson said that when he was contemplating purchasing Louisiana. And having said that by purchasing it he would make the Constitution a blank sheet of paper, he went ahead and purchased Louisiana.

Diversity in the service of freedom might be a very good thing. Diversity in the service of slavery might be a very bad thing.

He didn't care whether slavery was voted up or down, he cared only for the sacred right of the people to make that decision. Why the right of the people should have been sacred, if the results of the exercise of that right were indifferent, Douglas never undertook to say.