Lincoln had virtually retired from politics by 1854, having failed to obtain a much-coveted position in the Administration of Zachary Taylor. Then came the passage of the Kansas-Nebraska Act, Stephen Douglas's masterwork, which permitted the extension of slavery into the territories. Lincoln was horrified. In his view, slavery was like a cancer—or a "wen," as he called it. It could be eliminated only if it was first contained. If it ever metastasized, spreading into the new territories, it could never be stopped. He viewed the Kansas-Nebraska Act as a stimulant to the growth of the cancer because it invited slave-owning "squatters" to settle in the new territories, create electoral majorities, and establish new slave states. One of the longest and most passionate of Lincoln's speeches was his 1854 address on the act, which rehearsed many of the themes that would reappear in his debates with Douglas.
Douglas had boasted that the Kansas-Nebraska Act furthered democracy by leaving the question of whether or not to adopt slavery up to the people in the territories. Lincoln quickly homed in on the critical weakness in this "self-government" argument: "When the white man governs himself, that is self-government; but when he governs himself and also governs another man, that is more than self-government—that is despotism." It would not be despotism, of course, if slaves were not human: "That is to say, inasmuch as you do not object to my taking my hog to Nebraska, therefore I must not object to you taking your slave." This, Lincoln said, "is perfectly logical, if there is no difference between hogs and negroes." Lincoln kept returning to the question of the humanity of slaves, the question that Douglas ruled out of bounds as essentially "religious." Everywhere, Lincoln said, even in the South, people knew that slaves were human beings. If southerners really believed that slaves were not human, why did they join in banning the international slave trade, making it a capital offense? And if dealing in human flesh was no different from dealing in hogs or cattle, why was the slave-dealer regarded with revulsion throughout the South?
You despise him utterly. You do not recognize him as a friend, or even as an honest man. Your children must not play with his; they may rollick freely with the little negroes, but not with the "slave-dealers" children. If you are obliged to deal with him, you try to get through the job without so much as touching him.
People's moral intuitions could not be repressed; they would surface in all kinds of unexpected ways: in winces and unguarded expressions, in labored euphemisms, in slips of the tongue. Lincoln was on the lookout for these, and he forced his opponents to acknowledge their significance: "Repeal the Missouri Compromise—repeal all compromises—repeal the declaration of independence—repeal all past history, you still can not repeal human nature. It will still be the abundance of man's heart, that slavery extension is wrong; and out of the abundance of his heart, his mouth will continue to speak."
Douglas tried to evade the force of these observations by insisting that he didn't care what was chosen; all he cared about was the freedom to choose. At one point Douglas even tried to put his own theological spin on this, suggesting that God placed good and evil before man in the Garden of Eden in order to give him the right to choose. Lincoln indignantly rejected this interpretation. "God did not place good and evil before man, telling him to make his choice. On the contrary, he did tell him there was one tree, of the fruit of which, he should not eat, upon pain of certain death. I should scarcely wish so strong a prohibition against slavery in Nebraska."
Lincoln's depiction of slavery as a moral cancer became the central theme of his speeches during the rest of the 1850s. It was the warning he meant to convey in his "House Divided" speech, in his seven debates with Douglas in 1858, and in the series of speeches that culminated in the 1860 presidential campaign. In all these he continually reminded his audience that the theme of choice without reference to the object of choice was morally empty. He would readily agree that each state ought to choose the kind of laws it wanted when it came to the protection and regulation of its commerce. Indiana might need cranberry laws; Virginia might need oyster laws. But "I ask if there is any parallel between these things and this institution of slavery." Oysters and cranberries were matters of moral indifference; slavery was not.
The real issue in this controversy—the one pressing upon every mind—is the sentiment on the part of one class that looks upon the institution of slavery as a wrong, and of another class that does not look upon it as a wrong. The sentiment that contemplates the institution of slavery in this country as a wrong is the sentiment of the Republican party.
Lincoln has been portrayed as a moral compromiser, even an opportunist, and in some respects he was. Though he hoped that slavery would eventually be abolished within its existing borders, he had no intention of abolishing it. Although he said, in his "House Divided"speech of 1858, that "this government cannot endure, permanently half slave and half free," Lincoln made it clear in that speech, and in subsequent speeches and writings, that his intention was not to abolish slavery but to "arrest the further spread of it, and place it where the public mind shall rest in the belief that it is in course of ultimate extinction. . . ." In his first inaugural address, desperate to keep the South in the Union, he even hinted that he might support a constitutional amendment to protect slavery in the existing slave states against abolition by the federal government—a kind of reverse Thirteenth Amendment. The following year he countermanded an order by one of his own generals that would have emancipated slaves in South Carolina, Georgia, and Florida. In that same year he wrote the much-quoted letter to Horace Greeley stating that his "paramount object" was not to free slaves but to save the Union, and that if he could save the Union without freeing a single slave, he would do it. But when it came down to the commitment he had made in the 1850s, Lincoln was as stern as a New England minister. Slavery, he insisted, was an evil that must not be allowed to expand—and he would not allow it to expand. He struggled with a variety of strategies for realizing that principle, from gradual, compensated emancipation to outright abolition, but he never for a moment swerved from the principle. A month after his election Lincoln replied in this way to a correspondent who urged him to temper his opposition to slavery in the territories: "On the territorial question, I am inflexible. . . . You think slavery is right and ought to be extended; we think it is wrong and ought to be restricted."