Well, that is a key point of disagreement.
The Constitution was ratified by states, by sovereign states, not by the American people in mass. This is the history of the legalism of ratification. Going back of the legalism, another story emerges out of the records of those times. Beard in his work, An Economic Interpretation of the Constitution of the United States, made the following analysis: The movement for the Constitution was engineered by money, public securities, manufactures, trade and shipping. The initial steps in the forming of a new Constitution were taken by a small group of property interests. No popular vote was taken for the calling of the convention which drafted the Constitution. A very large class of persons without property had no representatives, and no voice in the convention. The delegates to the convention themselves had an economic interest in the formation of a new government. The Constitution drafted was an economic document. Three fourths of the adult males in the states failed to vote for delegates who ratified the Constitution, either positively abstaining from voting or else they were disfranchised by property qualifications. The Constitution was ratified by not to exceed one sixth of the adult males. The delegates in the state conventions represented the same economic groups which were represented in the Constitutional Convention. Beard showed that it is questionable whether the delegates in New York, Massachusetts, New Hampshire, Virginia, and South Carolina were chosen by voters who approved of the Constitution. The vote in New York has been preserved for us by the Daily Advertiser, and this vote in New York may be taken as an intrepretation of the general public will in many of the states. Albany, Ulster, Duchess, Orange, Columbia, Montgomery, Suffolk, and Washington Counties polled 11,230 Anti-Federalist votes; and 5496 Federal votes. The former thereby won 41 delegates to the state convention. New York County, Westchester, Queens, Kings, Richmond won but 25 delegates. With the apportionment against them, the Anti-Federalists thus elected twice as many delegates as the Federalists.
Returning to the Union and government under the Constitution which Lincoln said he was sworn by an oath to defend and protect, while no one had an oath registered in heaven to destroy them, there is a popular supposition that in some way the states lost their sovereignty by the ratification of the Constitution; or if they did not suffer quite so serious a deprivation that there were clauses in the Constitution which made the government under it supreme, whereas the government under the Articles was limited. In this connection much has been said of the clause in the Constitution which reads: "This constitution, and the laws of the United States which shall be made in pursuance thereof; and all treaties made, or which shall be made, under the authority of the United States, shall be the supreme law of the land; and the judges in every state shall be bound thereby, anything in the Constitution or laws of any state to the contrary notwithstanding." But by Article XIII of the Articles of Confederation it was provided: "Every state shall abide by the determinations of the United States in Congress assembled, on all questions which by this confederation is submitted to them. And the Articles of this Confederation shall be inviolably observed by every state, and the union shall be perpetual." In truth all conventions and compacts between sovereigns are the supreme law of the land. A treaty between Great Britain and the United States would be the supreme law in both realms, and binding upon the sovereignties and upon the subjects and citizens of both governments without any clause to that effect in the organic law of either government. This must be so in the nature of things; and it is so by the express law of nations. The courts of both are bound to hold a treaty to be supreme, and no constitutional clause is necessary to empower them so to hold. And it is to be observed that only laws and treaties which are made in pursuance of the Constitution are the supreme law; whence it follows that the Federal government was in this clause expressed to be one of limited powers, and that obedience to it is due only to the circumscribed extent that it legislates and makes treaties consonant to the grant of powers from the states expressed in the Constitution.
This discussion of Lincoln's theories of the Union and the Constitution, naturally leads to a consideration of the right of secession which the Southern states asserted, and which Lincoln resisted by the waging of one of the most cruel and bloody wars of history. If the right or wrong of slavery was in his opinion not sufficiently clear to warrant him in denouncing those who had slaves, as he said, the right or wrong of secession was certainly not clear enough to justify the killing of thousands of men for the purpose of demonstrating by arms its wrong. The truth is Lincoln did not know the Constitution and its history sufficiently well to have a well based opinion on this subject. It is perhaps true that he was not aware of the fact that Webster, whom he followed, had modified his views on the nature of the Union, and the rights of states under it. As we have seen, Webster in 1830 had debated these vexed questions with Hayne, and in 1833 with Calhoun. In 1839 he expressed himself very differently from what he had done on those prior occasions. In January of the latter year he argued the case of The Bank of Augusta against Earle in the Supreme Court, when he used this language in addressing the Court: "But it is argued, that though this law of comity exists as between independent nations, it does not exist between the states of this Union.... In respect to this law of comity, it is said, states are not nations; a sort of residuum of sovereignty is all that remains to them. The National sovereignty, it is said, is conferred on this government, and part of the municipal sovereignty.... Suppose that this Constitution had said, in terms after the language of the court below-all national sovereignty shall belong to the United States; all municipal sovereignty to the several states. I will say, that however clear, however distinct, such a definition may appear to those who use it, the employment of it, in the Constitution, could only have led to utter confusion and uncertainty. I am not prepared to say that the states have no national sovereignty. The laws of some of the states, Maryland and Virginia, for instance, provide punishment for treason. The power thus exercised is certainly not municipal.... The term sovereignty does not occur in the Constitution at all. The Constitution treats states as states and the United States as the United States; and by a careful enumeration, declares all the powers that are granted to the United States, and all the rest are reserved to the states.... The states of this Union, as states, are subject to all the voluntary and customary laws of nations." The Supreme Court, in passing on the case which Webster had thus argued, said: "It has, however, been supposed that the rules of comity between foreign nations do not apply to the states of this Union; that they extend to one another no other rights than those which are given by the Constitution... and that the courts are not at liberty to presume, in the absence of all legislation on the subject, that a state has adopted the comity of nations toward the other states.... The Court thinks otherwise. The intimate union of these states, as members of the same great political family; the deep and vital interests which bind them so closely together; should lead us, in the absence of proof to the contrary, to presume a greater degree of comity and friendship and kindness towards one another, than we should be authorized to presume between foreign nations. And when (as without doubt must occasionally happen) the interest or policy of any state requires it to restrict the rule, it has but to declare its will, and the legal presumption is at once at an end. But until this is done, upon what grounds could this court refuse to administer the law of international comity between these states? They are sovereign states.... We think it is well settled that by the law of comity among nations, a corporation created by one sovereignty is permitted to make contracts in another, and to sue in its courts; and that the same law of comity prevails among the several sovereignties of this Union."
Was Lincoln familiar with the letter which Webster wrote to the Barings in London in the year 1839? They had asked him for a legal opinion as to whether the legislature of one of the states had the legal and constitutional power to contract loans at home and abroad. "To this I answer," wrote Webster, "that the legislature of a state has such power; and how any doubt could have arisen on this point it is difficult for me to conceive. Every state is an independent, sovereign, political community, except in so far as certain powers, which it might otherwise have exercised, have been conferred on a General Government, established under a written Constitution, and exerting its authority over the people of all the states. This general government is a limited government. Its powers are specific and enumerated. All powers not conferred upon it still remain with the states and with the people. The state legislatures on the other hand, possess all usual and extraordinary powers of government, subject to any limitations which may be imposed by their own constitutions, and with the exception, as I have said, of the operation of those powers of the Constitution of the United States." If Lincoln had read this and absorbed its truth he never would have delivered the Cooper Institute Speech.
SOURCE: Edgar Lee Masters, Lincoln, The Man, Copr 1931, Reprint 1997, pp. 332-6.