“What doesn’t belong is your claim that our Founders ever favored disunion or secession “at pleasure”, meaning absent either mutual consent or necessity caused by oppression & usurpations.”
Here’s the language for which you have been searching:
“The powers not delegated to the Unted States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people except that the powers reserved for the people can not be exercised at pleasure or without the mutual consent of the federal government.”
Isn’t this what you really believe?
Isn’t this what you really believe?"
No, because "power" to break the law is not a "power", it's a crime, period.
The Constitution is a legally binding document, created from both necessity and mutual consent, which provides within itself multiple methods for addressing & redressing grievances.
It does not specifically address disunion, but our Founders' examples on that should be more than adequate: disunion from mutual consent or necessity, those are legit.
Disunion "at pleasure" is not.
And just so we're clear on this, my opinion is precisely that of Founders like James Madison ("Father of the Constitution") and such 1860 leaders as Democrat President Buchanan and Republican President-elect Lincoln, along with former living presidents Van Buren (Democrat), Fillmore (Whig) and Pierce (Democrat).
All believed in 1860 that Deep South Fire Eaters' declarations of secession were not constitutional or lawful.
They also believed, to a man, the Federal government could use no force to stop secessions, unless secessionists started war, which, of course, they soon did.
So all you Lost Causers wish to debate the legitimacy of secession, but the fact is there was no debate in 1860, since everyone understood it was unlawful, but could not be stopped unless secessionists themselves started war.
Which is exactly what President Lincoln said in his First Inaugural:
That's it, in a nutshell.