No, not "disingenuous", factual.
In fact, secessionists had no legitimate grievance, only exaggerated fears of what a President-elect Lincoln might do at some point in the future.
So secession was purely preemptive.
The truth is that by 1860 the great Slave Power had all but made slavery constitutionally legal in every state -- through the Compromise of 1850 shifting responsibility for enforcing Fugitive Slave Laws from state to Federal government, and the Supreme Court's 1857 Dred-Scott decision making all slaves perpetual slaves regardless of which state they moved to.
Lincoln was the first openly anti-slavery president ever elected, and even he only promised to restrict slavery from territories which didn't want it.
So the Slave Power's declarations of secession were, in fact, strictly "at pleasure" for no real reason except their fears of what might happen in the future.
moehoward: "It would appear that South Carolina did use "available constitutional remedies".
They did nothing of the sort.
Within days of Lincoln's election on November 6, 1860, South Carolina called for a secession convention which met in December and immediately declared secession, more than two months before Lincoln's inauguration.
They made no efforts to seek "mutual consent" from Congress, sought no redress from the Supreme Court, and provided no list of real grievances in their formal "Reasons for Secession" document.
It was strictly secession "at pleasure".
moehoward: "Buchanan may have been against secession but he believed states had the right, and the Court agreed and ruled as much in Dred and Kentucky v. Dennison."
On all three items, you have it wrong.
First, out-going President Buchanan was opposed to unilateral, unapproved secession on Constitutional grounds, and said so forcefully, in his 1860 State of the Union address.
But Buchanan also refused to use military force to stop secession, a policy that Lincoln intended to follow, so long as secessionists did not start a war.
Second, the Supreme Court's decisions in both Dred-Scott and Kentucky v. Dennison had nothing to do with secession, period.
They both strengthened the rights of slave-holders to transport slaves through non-slave states without losing their "property rights".
And Kentucky v. Dennison is irrelevant to this discussion because it involved the Union states of Ohio and Kentucky, and was issued in 1861, after the Deep South had already declared secession.
I said "Buchanan may have been against secession..."
And both cases I cite found the "General Government" powerless to force a state governor to act.
According to American Legal History 2nd ed., the Chief Justice opinion in Kentucky v Dennison "was obviously meant to deny Lincoln the power to coerce states back into the Union".
My recollection of their grievances includes past controversies resolved at the supreme court, to include the resolution of Personal Liberty laws, which was decided in favor of the Slave Power.