By the repeal of the Missouri Compromise, opening the Territories to the ingress of slavery, Douglas had pleased the South, but greatly alarmed the North. He had sought to conciliate Northern sentiment by appending to his Kansas-Nebraska Bill the declaration that its intent was "not to legislate slavery into any State or Territory, nor to exclude it therefrom, but to leave the people thereof perfectly free to form and regulate their institutions in their own way, subject only to the Constitution of the United States." This he called "the great principle of popular sovereignty." When asked whether, under this act, the people of a Territory, before its admission as a State, would have the right to exclude slavery, he answered, "That is a question for the courts to decide." Then came the famous "Dred Scott decision," in which the Supreme Court held substantially that the right to hold slaves as property existed in the Territories by virtue of the Federal Constitution, and that this right could not be denied by any act of a territorial government.
This, of course, denied the right of the people of any Territory to exclude slavery while they were in a territorial condition, and it alarmed the Northern people still more. Douglas recognized the binding force of the decision of the Supreme Court, at the same time maintaining, most illogically, that his great principle of popular sovereignty remained in force nevertheless. Meanwhile, the proslavery people of western Missouri, the so-called "border ruffians," had invaded Kansas, set up a constitutional convention, made a constitution of an extreme pro-slavery type, the "Lecompton Constitution," refused to submit it fairly to a vote of the people of Kansas, and then referred it to Congress for acceptance,--seeking thus to accomplish the admission of Kansas as a slave State. Had Douglas supported such a scheme, he would have lost all foothold in the North. In the name of popular sovereignty he loudly declared his opposition to the acceptance of any constitution not sanctioned by a formal popular vote. He "did not care," he said, "whether slavery be voted up or down," but there must be a fair vote of the people. Thus he drew upon himself the hostility of the Buchanan administration, which was controlled by the proslavery interest, but he saved his Northern following. More than this, not only did his Democratic admirers now call him "the true champion of *******," but even some Republicans of large influence, prominent among them Horace Greeley, sympathizing with Douglas in his fight against the Lecompton Constitution, and hoping to detach him permanently from the proslavery interest and to force a lasting breach in the Democratic party, seriously advised the Republicans of Illinois to give up their opposition to Douglas, and to help re-elect him to the Senate. Lincoln was not of that opinion. He believed that great popular movements can succeed only when guided by their faithful friends, and that the antislavery cause could not safely be entrusted to the keeping of one who "did not care whether slavery be voted up or down." This opinion prevailed in Illinois; but the influences within the Republican party over which it prevailed yielded only a reluctant acquiescence, if they acquiesced at all, after having materially strengthened Douglas's position. Such was the situation of things when the campaign of 1858 between Lincoln and Douglas began.
Lincoln opened the campaign on his side at the convention which nominated him as the Republican candidate for the senatorship, with a memorable saying which sounded like a shout from the watchtower of history: "A house divided against itself cannot stand. I believe this government cannot endure permanently half slave and half free. I do not expect the Union to be dissolved.
I do not expect the house to fall, but I expect it will cease to be divided. It will become all one thing or all the other.
Either the opponents of slavery will arrest the further spread of it, and place it where the public mind shall rest in the belief that it is in the course of ultimate extinction, or its advocates will push it forward, till it shall become alike lawful in all the States,--old as well as new, North as well as South." Then he proceeded to point out that the Nebraska doctrine combined with the Dred Scott decision worked in the direction of ****** the nation "all slave." Here was the "irrepressible conflict" spoken of by Seward a short time later, in a speech made famous mainly by that phrase. If there was any new discovery in it, the right of priority was Lincoln's. This utterance proved not only his statesmanlike conception of the issue, but also, in his situation as a candidate, the firmness of his moral courage. The friends to whom he had read the draught of this speech before he delivered it warned him anxiously that its delivery might be fatal to his success in the election. This was shrewd advice, in the ordinary sense. While a slaveholder could threaten disunion with impunity, the mere suggestion that the existence of slavery was incompatible with ******* in the Union would hazard the political chances of any public man in the North. But Lincoln was inflexible. "It is true," said he, "and I will deliver it as written.... I would rather be defeated with these expressions in my speech held up and discussed before the people than be victorious without them." The statesman was right in his far- seeing judgment and his conscientious statement of the truth, but the practical politicians were also right in their prediction of the immediate effect. Douglas instantly seized upon the declaration that a house divided against itself cannot stand as the main objective point of his attack, interpreting it as an incitement to a "relentless sectional war," and there is no doubt that the persistent reiteration of this charge served to frighten not a few timid souls.