The Gadsden treaty was also strongly opposed and condemned by Benton, who considered it to be part of a great scheme or movement in the interests of the slavery disunionists, of which he also believed the Kansas-Nebraska bill to be the first development,--the "thin end of the wedge." He opposed the acquirement even of the small piece of territory we were actually able to purchase from Mexico; and showed good grounds for his belief that the administration, acting as usual only in the interest of the secessionists, had tried to get enough North-Mexican territory to form several new states, and had also attempted to purchase Cuba, both efforts being for the purpose of enabling the South either to become again dominant in the Union or else to set up a separate confederacy of her own. For it must be kept in mind that Benton always believed that the Southern disunion movements were largely due to conspiracies among ambitious politicians, who used the slavery question as a handle by which to influence the mass of the people. This view has certainly more truth in it than it is now the fashion to admit. His objection to the actual treaty was mainly based on its having been done by the executive without the consent of the legislature, and he also criticised it for the secrecy with which it had been put through. In bringing forward the first objection, however, he was confronted with Jefferson's conduct in acquiring Louisiana, which he endeavored, not very successfully, to show had nothing in common with the actions of Pierce, who, he said, simply demanded a check from the House with which to complete a purchase undertaken on his own responsibility. Throughout his congressional term of service, Benton acted so as to deserve well of the Union as a whole, and most well of Missouri in particular. But he could not stem the tide of folly and madness in this state, and was defeated when he was a candidate for reëlection. The Whigs had now disappeared from the political arena, and the Know-nothings were running through their short and crooked lease of life; they foolishly nominated a third candidate in Benton's district, who drew off enough votes from him to enable his pro-slavery Democratic competitor to win.