Declining to become a candidate for renomination to Congress, Lincoln returned to Springfield, partially withdrew from politics, and devoted himself largely to the practice of law. He reappeared as an active participant in politics in Illinois in 1854, when there appeared a new aspect of the question as reflected by the debate incident to the Kansas-Nebraska controversy. At this time Lincoln was called for in all directions to deliver addresses to inform the people on the issue of the day. In this connection he demonstrated his inalterable opposition to the extension of slavery.[6] He objected to the iniquitous doctrine of the Nebraska Bill in that it assumed that there was moral right in the enslaving of one man by another, and, further, that it tended to be unmistakably subversive of the basic principles of the Declaration of Independence. Lincoln was of the opinion that the salvation of the Union was dependent upon the extension or the restriction of slavery. Realizing the futility and the hopelessness of voluntary emancipation, he asserted that the "Autocrat of all the Russias" would resign his crown, and proclaim freedom to all his subjects sooner than the "American masters" would voluntarily give up their slaves.[7] It is remarkable that Lincoln's speculative affirmation was followed by what he thought an impossibility, for on the day preceding Mr. Lincoln's inauguration the "Autocrat of all the Russias," Alexander II, by an imperial decree emancipated his serfs; "while six weeks after the inauguration, the proslavery element, headed by Jefferson Davis, began the Rebellion to perpetuate and to spread the institution of slavery." In 1857 came the Dred Scott decision, in which Chief Justice Taney of the Supreme Court dragged that tribunal into politics, aiming to settle the question of slavery in the territories, but it stimulated rather than suppressed the discussion of slavery, as was evident by its outburst in the debates between Mr. Lincoln and Mr. Stephen A. Douglas.[8] The main question was whether, according to the Constitution, Congress could prohibit slavery in the territories. Lincoln contended that it could but Douglas was evasive, as he hoped to reconcile his popular sovereignty with the Dred Scott decision. Lincoln, on the other hand, showed that the public estimate of the Negro had become decidedly lower than it was prior to the industrial revolution, when masters could emancipate their bondmen of their own volition. Since then it had become common for the State Legislature, which in the exercise of the sovereignty of the State had the power to abolish slavery within its limits, to withhold that power and to make legal restraints tantamount to prohibition.