Elbert B. Smith, a professor of history at the University of Maryland and a revisionist when it comes to certain antebellum presidents, writes the following about Buchanan and secession in presidentprofiles.com: "Just as Buchanan had contributed significantly to the election of Lincoln, he now aided the secession effort in states where the issue might have been in doubt...
"The South needed reassurances, but not a presidential endorsement for secessionist arguments. Buchanan, however, blamed the crisis entirely on the 'intemperate interference of the Northern people with the question of slavery.' Congressional and territorial efforts to exclude slavery from the territories and state violations of the fugitive-slave laws could have been endured, he said, but 'the incessant and violent agitation of the slavery question' had produced its 'malign influence on the slaves... Many a matron throughout the South retires at night in dread of what may befall herself and her children before the morning... no political union, however fraught with blessings and benefits' could endure 'if the necessary consequence be to render the homes and firesides of nearly half the parties to it habitually and hopelessly insecure. Sooner or later the bonds of such a Union must be severed.'
"After admitting that certain grievances would justify secession, Buchanan argued rather brilliantly that secession was unconstitutional, saying that the Founding Fathers had never intended any such right and 'the solemn sanction of religion' had been added in the oaths of office taken by federal and state officers. He suggested, however, that secession might be justified if it was called revolution instead of an inherent constitutional right.... The federal government, therefore, had no power either to recognize secession or to coerce any state to remain in the Union. And finally, said Buchanan, either Congress or the states should call a constitutional convention that could emphasize the duty of the federal government to protect slavery in all the territories throughout their territorial existence, reconfirm the right of masters to have escaped slaves returned, and declare all Northern state laws hindering this process to be null and void.
"Buchanan had clearly learned nothing from the election of 1860. John Breckinridge, with a platform that embodied Buchanan's suggestions, had received almost no Northern votes and had not even won a popular majority in the slaveholding states. Federal protection for slavery where a popular majority opposed it violated a basic precept of democracy and had already been rejected overwhelmingly by Northern voters.
"Thus, the president defended the Southerners' own excuses for secession, denied them any such right, announced that he would not coerce them, and declared that secession could be prevented only by concessions that every Southerner knew would never be made. The impact of his message on the secession conventions cannot be measured, but it must have weakened the Unionists, who were strong in several Southern states. To Northerners, the message was further evidence that Southerners were ruling the country, and it probably made most of them even less receptive to compromise proposals. Southerners, on the other hand, found their radical arguments vindicated but were angered by Buchanan's refusal to admit the right of secession.
"Just two days before the secession of South Carolina, a Senate committee headed by John J. Crittenden offered a plan to extend the Missouri Compromise line to the Pacific, but Southerners and Northerners alike rejected it.... Buchanan sent an emissary to Illinois with a plea for Lincoln to join him in a call for a national referendum on the Crittenden proposals, but the president-elect refused. Lincoln quite correctly believed that the South would accept no concessions less than those already rejected by Northerners in the 1860 election....
"Buchanan, meanwhile, continued to act as though the 1860 election had never occurred. Secession, he argued, had been caused by a misapprehension in the South of the true feelings of the Northern people and a transfer of the question 'from political assemblies to the ballot box... would speedily redress the serious grievances which the South had suffered.' Unfortunately for Buchanan's aspirations, nothing the North would offer could keep the lower South from seceding, and nothing would induce Abraham Lincoln to accept a division of the Union. Neither James Buchanan nor a national convention could change these facts."