You make it sound like a more perfect Union.
And that, of course, is exactly what made it more perfect: they skipped the middlemen (state governments) and went straight to "
the ultimate source of all governing power." As a result, no one but the sovereign people of the US can alter or abolish their Union. If the people have not specifically delegated such a power to anyone else via the Constitution ("
New States may be Admitted by the Congress into this Union;..."), they must be consulted directly on any such question (existing states leaving the Union).
There are several points on which unilateral secession fails. Sovereignty is one, and perpetual Union is another. I have my own problems with TX v. White. Chase chose a subject as good as any other: perpetual Union. He just failed to explain WHY perpetual was perfect to the Founders. The idea that perpetuity was necessary in 1777, and abandoned in 1787, without any discussion, without so much as a word on such a momentous change, is ludacris. However, we don't need to assume anything:
"
In all our deliberations on this subject we kept steadily in our view, that which appears to us the greatest interest of every true American, the consolidation of our Union, in which is involved our prosperity, felicity, safety, perhaps our national existence." -- Official Letter of the Constitutional Convention, September 17, 1787
What do secessionists presume? That a perpetual Union loses the aspect of perpetuity when it is consolidated? Besides the obvious fallacy of that notion (the whole reason for switching from the AOCs to the Constitution was because the former appeared to be on the verge of providing perpetuity), the Framers indicated that the Constitution was not just for the founding generation of Americans, but also for their "
Posterity," which means "
all future generations." They even stressed that particular word via capitalization.
"
It is worthy of remark that not only the first, but every succeeding Congress, as well as the late convention, have invariably joined with the people in thinking that the prosperity of America depended on its Union. To preserve and perpetuate it was the great object of the people in forming that convention, and it is also the great object of the plan which the convention has advised them to adopt. With what propriety, therefore, or for what good purposes, are attempts at this particular period made by some men to depreciate the importance of the Union? Or why is it suggested that three or four confederacies would be better than one? I am persuaded in my own mind that the people have always thought right on this subject, and that their universal and uniform attachment to the cause of the Union rests on great and weighty reasons, which I shall endeavor to develop and explain in some ensuing papers. They who promote the idea of substituting a number of distinct confederacies in the room of the plan of the convention, seem clearly to foresee that the rejection of it would put the continuance of the Union in the utmost jeopardy. That certainly would be the case, and I sincerely wish that it may be as clearly foreseen by every good citizen, that whenever the dissolution of the Union arrives, America will have reason to exclaim, in the words of the poet: 'FAREWELL! A LONG FAREWELL TO ALL MY GREATNESS.' " -- John Jay, The Federalist No. 2