The way I look at it, the right of secession is still an interesting subject. If the states still have that right, which I believe they do, in theory, if Hillary wins the next election, the red states can just secede....:)
And if they did indeed have the right of secession, then Lincoln was wrong.
You open fire on American troops, you reap the whirlwind.
As I understand it, any state could have taken a suit direct to the Supreme Court to determine this. No state chose to do so, largely due to internal politics of forcing waverers to join the secessionists. Instead, they chose to wage war on the federal government.
They didn't want a peaceful secession of a few of the Deep South states, which is all they would have got that way. Such a Confederacy would have been unsustainable. They wanted violent emotions to be inflamed which would lead moderates to spring to the defense of their "brothers."
Worked, too, almost well enough to win the war.
As for forgetting "after 140 years": there were far too many dastardly atrocities committed against unarmed, innocent Southern citizenry, both black and white. To this day, the deeds of units from Ohio, Illinois, and especially the murderous units from Indiana I believe place them in hell for what they did.
Not a lot gets said about this, but there are plenty of records of war crimes upon war crimes by these consciousless, heartless thugs, rapists, thieves, and murderers.
Don't ever forget, Texas (and Louisiana, Arkansas, Mississippi, Tennessee, Alabama, Georgia, Florida, South Carolina, North Carolina, Virginia..) Never forget these murderous devils or their crimes.
Secession? I am still for it. It may take a number of decades to accuate the start of it, but I believe a new country is the only solution to what is left here.