Buchanan, a pliant tool, was elected by a plurality vote over Fremont and Fillmore, the candidate of the American party. Fremont carried, with good majorities, all the free States save Indiana, New Jersey, Pennsylvania, Illinois, and California. The popular discussion of the slavery question in the campaign was thorough, memorable, exciting, educating, and, though resulting in defeat to the anti-slavery party, it marked the trend of public sentiment, and clearly foreshadowed that it would soon triumph. The Lincoln-Douglas debates of 1858 still further elucidated to the masses of the people the issues impending, and indicated that the end of slavery extension was near. The Dred Scott decision, announced March, 1857, had completely overthrown, so far as it could be done by judicial-political _obiter dicta_, Douglas's Popular Sovereignty theory, leaving him with only the northern end (and that not united) of his party endeavoring to uphold it. Next came the Presidential campaign of 1860, the last in which a slave party participated. The Democratic party met in delegate convention in April, 1860, in Charleston, South Carolina, and after seven days of struggle, during which disunion threats were made by Yancey and others, the delegates from the Cotton States--South Carolina, Alabama, Mississippi, Louisiana, Florida, Texas, and Arkansas--seceded, for the alleged reason that a majority of the convention adopted the 1856 Democratic platform which upheld the Douglas - Popular Sovereignty doctrine as applied to the Territories. The seceding delegates had voted for a platform declaring the right of all citizens to settle in the Territories with all their property (including slaves) "without its being destroyed or impaired by Congressional or territorial legislation," and further, "That it is the duty of the Federal Government in all its departments to protect, when necessary, the rights of persons and property in the Territories, and wherever else its constitutional authority extends." This was not only the new doctrine of the Supreme Court, but to it was superadded the further claim that the Constitution _required_ Congress and all the departments of the government to protect the slaveholder with his slaves, when once in a Territory, against territorial legislation or other unfriendly acts. By this most startling doctrine the Constitution was to become an instrument to _establish and protect slavery_ in all the territorial possessions of the Republic.