All things considered, Douglas's line of argument was as well sustained as any presented by the supporters of the war. The absence of any citations to substantiate important points was of course due to the impromptu nature of the speech. Two years later,[225] in a carefully prepared speech constructed on much the same principles, he made good these omissions, but without adding much, it must be confessed, to the strength of his argument. The chain of evidence was in fact no stronger than its weakest link, which was the so-called treaty of Santa Anna with the President of the Republic of Texas. Nowhere in the articles, public or secret, is there an express recognition of the independence of the Republic, nor of the boundary. Santa Anna simply pledged himself to do his utmost to bring about a recognition of independence, and an acknowledgment of the claims of Texas to the Rio Grande as a boundary.[226] Did Douglas misinterpret these articles, or did he chance upon an unauthentic version of them? In the subsequent speech to which reference has been made, he cited specific articles which supported his contention. These citations do not tally with either the public or secret treaty. It may be doubted whether the secret articles were generally known at this time; but the open treaty had been published in Niles' _Register_ correctly, and had been cited by President Polk.[227] The inference would seem to be that Douglas unwittingly used an unauthenticated version, and found in it a conclusive argument for the claim of Texas to the disputed territory.