There are a number of ways to advancing the argument, but time is limited for me, so here is the short version:
Articles of Confederation
States could not secede under the Articles. The Union was perpetual and inviolate, no one state could leave.
Thomas Jefferson, himself used as a proponent of secession, even opined that under the Articles, force could be used to coerce states into remaining in the Union:
It has been so often said, as to be generally believed, that Congress have no power by the Confederation to enforce anything; for example, contributions of money. It was not necessary to give them that power expressly; they have it by the law of nature. When two parties make a compact, there results to each a power of compelling the other to execute it. Compulsion was never so easy as in our case, where a single frigate would soon levy on the commerce of any State the deficiency of its contributions; nor more safe than in the hands of Congress, which has always shown that it would wait, as it ought to do, to the last extremities, before it would execute any of its powers which are disagreeable.
So, we know states retain no power to secede under the Articles. Good starting point. Then, we note that the whole point of the Constitution was to provide for a stronger federal government than what was under the Articles. Now, a secession power under the Constitution would make the federal government weaker than under the Articles - where the right of secession wasn’t before can’t be presumed to be added if the theory is to make the federal government even stronger than it was in the first incarnation.
That demonstrates Intent - no way the Founders would have permitted a power that would undermine the very project they had undertaken. That defies logic, common sense, and legal philosophy. Next up - Ratification.
Ratification of the Constitution
Pro-ratifiers didn’t think the Constitution created a league of states, they knew it was designed to be something different.
Hamilton:
[i]There is nothing absurd or impracticable in the idea of a league or alliance between independent nations for certain defined purposes precisely stated in a treaty�?�depending for its execution on the good faith of the parties. Compacts of this kind exist among all civilized nations�?�. In the early part of the [eighteenth] century there was an epidemical rage in Europe for this species of compacts, from which the politicians of the times fondly hoped for benefits which were never realized�?�. [T]hey were scarcely formed before they were broken, giving an instructive but afflicting lesson to mankind, how little dependence is to be placed on treaties which have no other sanction than the obligations of good faith, and which oppose general considerations of peace and justice to the impulse of any immediate interest or passion. If the particular States in this country are disposed to stand in a similar relation to each other, and to drop the project of a general DISCRETIONARY SUPERINTENDENCE, the scheme would indeed be pernicious, and would entail upon us all the mischiefs which have been enumerated�?�.
But if we are unwilling to be placed in this perilous situation; if we still will adhere to the design of a national government, or, which is the same thing, of a superintending power, under the direction of a common council, we must resolve to incorporate into our plan those ingredients which may be considered as forming the characteristic difference between a league and a government; we must extend the authority of the Union to the persons of the citizens,�??the only proper objects of government.[/i]
More Hamilton, on why the Articles won’t cut the mustard…
The great and radical vice in the construction of the existing Confederation is in the principle of LEGISLATION for STATES or GOVERNMENTS, in their CORPORATE or COLLECTIVE CAPACITIES, and as contradistinguished from the INDIVIDUALS of which they consist.
Patrick Henry (yes, of “give me liberty or give me death” fame) asked:
Who authorized [the Constitutional Convention] to speak the language of We the people, instead of We, the States? States are the characteristics, and the soul of a confederation.
Madison’s reply:
Should all the states adopt it, it will be then a government established by the thirteen states of America, not through the intervention of the legislatures, but by the people at large. In this particular respect, the distinction between the existing and proposed governments is very material. The existing system has been derived from the dependent derivative authority of the legislatures of the states; whereas this is derived from the superior power of the people�?�. Thus [the Constitution] is of a complicated nature; and this complication, I trust, will be found to exclude the evils of absolute consolidation, as well as of a mere confederacy. If Virginia was separated from all the states, her power and authority would extend to all cases: in like manner, were all powers vested in the general government, it would be a consolidated government; but the powers of the federal government are enumerated; it can only operate in certain cases; it has legislative powers on defined and limited objects, beyond which it cannot extend its jurisdiction.
These are all fun and good, and there are many more. But here is the more compelling issue - those opposed to the ratification of the Constitution opposed it precisely because it would not be a league of states, but a nation:
“Cincinnatus” wrote:
[s]uch is the anxiety manifested by the framers of the proposed constitution, for the utter extinction of the state sovereignties, that they were not content with taking from them every attribute of sovereignty, but would not leave them even the name.�??Therefore, in the very commencement they prescribe this remarkable declaration�??We the People of the United States.
“Brutus” complained:
It is ratified, [it] will not be a compact entered into by the States, in their corporate capacities, but an agreement of the people of the United States as one great body politic�?�. It is to be observed, it is not a union of states or bodies corporate; had this been the case the existence of the state governments might have been secured. But it is a union of the people of the United States considered as one body, who are to ratify this constitution, if it is adopted.
“Federal Farmer”:
when the people [of each state] shall adopt the proposed�?�it will be adopted not by the people of New Hampshire, Massachusetts, &c., but by the people of the United States…
So outside of the context that “retaining” a secession power that didn’t exist in the first place, both the proponents and the opponents of the ratification of the Constitution believed exactly the opposite of the “league of states” theory.
And, as an aside, as one law professor noted, if it had been understood that a secession power was available after ratification, it would have increased the chances of ratification significantly and the anti-federalists would have been few.
We know better - how? That was precisely why there was so much pushback on ratification: whatever rights a state has under a “league of states” framework (and we have already seen there was no secession right, but at any rate), they lost with the ratification of the Constitution, as it created a Union and a nation, not a treaty organization.
Kentucky and Virginia Resolutions.
Much is made of these, but when proposed to other state legislatures, the Resolutions were roundly rejected.
Plus, Madison - co-author of said Resolutions - had this to say to TJ:
Have you ever considered thoroughly the distinction between the power of the State, & that of the Legislature, on questions relating to the federal pact[?] On the supposition that the former is clearly the ultimate Judge of infractions, it does not follow that the latter is the legitimate organ especially as a convention was the organ by which the Compact was made.
More Madison:
[i][T]he characteristic peculiarities of the Constitution are 1. The mode of its formation, 2. The division of the supreme powers of Govt between the States in their united capacity and the States in their individual capacities. 1. It was formed, not by the Governments of the component States, as the Federal Govt. for which it was substituted was formed; nor was it formed by a majority of the people of the U.S. as a single community in the manner of a consolidated Government. It was formed by the States�??that is by the people in each of the States, acting in their highest sovereign capacity; and formed, consequently, by the same authority which formed the State Constitutions. Being thus derived from the same source as the Constitutions of the States, it has within each State, the same authority as the Constitution of the State, and is as much a Constitution, in the strict sense of the term, within its prescribed sphere, as the Constitutions of the States are within their respective spheres, but with this obvious & essential difference, that being a compact among the States in their highest sovereign capacity, and constituting the people thereof one people for certain purposes, it cannot be altered or annulled at the will of the States individually, as the Constitution of a State may be at its individual will.
As for Jefferson, though used as a proponent for the right to secession, he isn’t much use - he believed under the Articles that force could be used to keep states in the Union, and he actually prosecuted Aaron Burr for an attempted secession in Western American. TJ was a complex man - and not much help determining the issue.
Legal and Philosophical Arguments.
These have been covered before, over and over, so I won’t repeat myself, although the really, really smart Orion is certain they haven’t (“I’m right! And I know it!”), but a quick bullet point review:
-Checks and balances of the document itself demonstrate the Framers had no expectation of a secession veto that could override all the mechanics of federal government
-The Supremacy Clause would not have been drafted if states retained secession and nullification powers
-The Constitution textually permits the right of the government to put down insurrections and rebellions
-The Constitution provides for its own amendment and abolition via proscribed procedures
Now, as to the looneytarian view of the Constitution and the Civil War - it defies history and common sense, neither of which is the looneytarian’s specialty.
But as stated earlier, Orion’s dumb ass wouldn’t even know if I was right or wrong on the matter - so it takes the sport out of the debate.
EDIT: forgot to add Madison’s reply to Patrick Henry.