Adams and Pearston apparently can't believe that many people once strongly supported slavery and considered it a necessary pillar of Southern society. A lot of people have trouble understanding or accepting that. So they construct a model in which slavery didn't matter, had no strong support, and was bound somehow to disappear on its own. From such a starting point, they don't have trouble concluding that slavery was a minor factor in bringing on secession and war, but their model is flawed, in so far as there definitely was support for preserving, protecting, and extending slavery and a panic about how a Republican President could damage slaveholders' interests.
I went back as far as 1828 and the The South Carolina "Exposition", drafted secretly by Vice-President John C. Calhoun, and presented to the state's House of Representatives on 19 December 1828 by a special committee charged with formulating a response to the federal protective tariff passed earlier that year.
"We cultivate certain great staples for the supply of the general market of the world; and they manufacture almost exclusively for the home market. Their object in the Tariff is to keep down foreign competition, in order to obtain a monopoly of the domestic market. The effect on us is to compel us to purchase at a higher price, both what we purchase from them and from others, without receiving a corresponding increase of price for what we sell. The price, at which we can afford to cultivate, must depend on the price at which we receive our supplies. The lower the latter, the lower we may dispose of our products with profit; and in the same degree our capacity of meeting competition is increased; on the contrary, the higher the price of our supplies, the less the profit at the same price, and the less consequently the capacity for meeting competition. . . . The case then, fairly stated between us and the manufacturing States, is, that the Tariff gives them a prohibition against foreign competition in our own market, in the sale of their goods, and deprives us of the benefit of a competition of purchasers for our raw material. They who say, that they cannot compete with foreigners at their own doors without an advantage of nearly fifty per cent., expect us to meet them abroad, under a disadvantage equal to their encouragement. But the oppression, great as it is to us, will not stop at this point. The trade between us and Europe, has heretofore been a mutual exchange of products. Under the existing duties, the consumption of European fabrics must in a great measure cease in our country, and the trade must become, on their part a cash transaction. But he must be ignorant of the principals of commerce, and the policy of Europe, particularly England, who does not see, that it is impossible to carry on a trade of such vast extent on any other basis but that of mutual exchange of products; and if it were not impossible, such a trade would not long be tolerated. We already see indications of the commencement of a commercial warfare, the termination of which cannot be conjectured, though our fate may easily be. The last remains of our great and once flourishing agriculture must be annihilated in the conflict. In the first instance we will be thrown on the home market, which cannot consume a fourth of our products; and instead of supplying the world, as we should with a free trade, we shall be compelled to abandon the cultivation of three-fourths of what we now raise, and receive for the residue, whatever the manufacturers, (who will then have their policy consummated, by the entire possession of their market, both exports and imports,) may choose to give.
Forced with an immense sacrifice of capital to abandon our ancient and favourite pursuit, to which our soil, climate, habits and peculiar labor are adapted, we should be compelled without experience or skill, and with a population untried in such pursuits, to attempt to become the rivals instead of the customers of the manufacturing States. The result is not doubtful. If they, by superior capital and skill, should keep down successful competition on our part, we should be doomed to toil at our unprofitable agriculture, selling at the prices, which a single and limited market might give. But on the other hand, if our necessity should triumph over their capital and skill, if, instead of raw cotton, we should ship to the manufacturing States, cotton yarn, and cotton goods, the thoughtful must see, that it would immediately bring about a state of things, which could not long continue. Those who now make war on our gains would then make it on our labour. They would not tolerate, that those, who now cultivate our plantations and furnish them with the material and market for the products of their arts, should, by becoming their rivals, take bread out of the mouths of their wives and children. The committee will not pursue this painful subject, but as they clearly see, that the system if not arrested, must bring the country to this hazardous extremity, neither prudence nor patriotism would permit them to pass it by, without giving warning of an event so full of danger. . . .
No government based on the naked principle, that the majority ought to govern, however true the maxim in its proper sense and under proper restrictions, ever preserved its liberty, even for a single generation. The history of all has been the same, injustice, violence and anarchy, succeeded by the government of one, or a few, under which the people seek refuge, from the more oppressive despotism of the majority. Those governments only, which provide checks, which limit and restrain within proper bounds the power of the majority, have had a prolonged existence, and been distinguished for virtue, power and happiness. Constitutional government, and the government of the majority, are utterly incompatible, it being the sole purpose of a constitution to impose limitations and checks upon the majority. An unchecked majority, is a despotism--and government is free, and will be permanent in proportion to the number, complexity and efficiency of the checks, by which it powers are controlled. . . .
That there exists a case which would justify the interposition of this State, and thereby compel the General Government to abandon an unconstitutional power, or to make an appeal to the amending power to confer it by express grant, the committee does not in the least doubt; and they are equally clear in the existence of a necessity to justify its exercise, if the General Government should continue to persist in its improper assumption of powers, belonging to the State; which brings them to the last point which they propose to consider. When would it be proper to exercise this high power? If they were to judge only by the magnitude of the interest and urgency of the case, they would without hesitation recommend the exercise of this power without delay. But they deeply feel the obligation of respect for the other members of the confederacy, and of great moderation and forbearance in the exercise, even of the most unquestionable right, between parties who stand connected by the closest and most sacred political union. With these sentiments, they deem it advisable after presenting the views of the Legislature in this solemn manner, to allow time for further consideration and reflection, in the hope that a returning sense of justice on the part of the majority, when they have come to reflect on the wrongs, which this and other staple States have suffered, and are suffering, may repeal the obnoxious and unconstitutional acts, and thereby prevent the necessity of interposing the sovereign power of this State.
The committee is further induced at this time to take this course, under the hope that the great political revolution which will displace from power on the 4th of March next, those who acquired authority by setting the will of the people at defiance; and which will bring in an eminent citizen, [Andrew Jackson,] distinguished for his services to his country and his justice and patriotism, may be followed up under his influence with a complete restoration of the pure principles of our government.
But in thus recommending delay, the committee wish it to be distinctly understood, that neither doubts of the power of the State, nor apprehension of consequences, constitute the smallest part of their motives. . . .
With these views the committee are solemnly of impression if the system be persevered in, after due forbearance on the part of the State, that it will be her sacred duty to interpose her veto; a duty to herself, to the Union, to present, and to future generations, and to the cause of liberty over the world, to arrest the progress of a power, which, if not arrested, must in its consequences, corrupt the public morals, and destroy the liberty of the country."
excerpted
Trouble was brewing as early as 1828.