The congressional record indicates otherwise in very clear terms.
You don't need to rehash a long winded speech from a two-bit southern politician, when you have an excellent primary source like the Georgia Statement of Secession. Here is another excerpt from it, and once again, slavery not tariffs is described as a Cause.
The feeling of anti-slavery, which it was well known was very general among the people of the North, had been long dormant or passive; it needed only a question to arouse it into aggressive activity. This question was before us. We had acquired a large territory by successful war with Mexico; Congress had to govern it; how, in relation to slavery, was the question then demanding solution. This state of facts gave form and shape to the anti-slavery sentiment throughout the North and the conflict began. Northern anti-slavery men of all parties asserted the right to exclude slavery from the territory by Congressional legislation and demanded the prompt and efficient exercise of this power to that end.
ref: Georgia Statement of Secession, January 29, 1861
The Georgia secession statement is an excellent example of 19th century white supremist demogogery. Have you even read it? Georgia Secession
Why not post em both when they offer complimentary positions on the tariff? Hunter's speech states the same grievances with the tariff that are in the part of the Georgia document I posted for you.
Georgia Senator Robert Toombs echoed the sentiments of both in his own speech from late 1860:
"Even the fishermen of Massachusetts and New England demand and receive from the public treasury about half a million of dollars per annum as a pure bounty on their business of catching codfish. The North, at the very first Congress, demanded and received bounties under the name of protection, for every trade, craft, and calling which they pursue, and there is not an artisan in brass, or iron, or wood, or weaver, or spinner in wool or cotton, or a calicomaker, or iron-master, or a coal-owner, in all of the Northern or Middle States, who has not received what he calls the protection of his government on his industry to the extent of from fifteen to two hundred per cent from the year 1791 to this day. They will not strike a blow, or stretch a muscle, without bounties from the government. No wonder they cry aloud for the glorious Union; they have the same reason for praising it, that craftsmen of Ephesus had for shouting, "Great is Diana of the Ephesians," whom all Asia and the world worshipped. By it they got their wealth; by it they levy tribute on honest labor. It is true that this policy has been largely sustained by the South; it is true that the present tariff was sustained by an almost unanimous vote of the South; but it was a reduction - a reduction necessary from the plethora of the revenue; but the policy of the North soon made it inadequate to meet the public expenditure, by an enormous and profligate increase of the public expenditure; and at the last session of Congress they brought in and passed through the House the most atrocious tariff bill that ever was enacted, raising the present duties from twenty to two hundred and fifty per cent above the existing rates of duty. That bill now lies on the table of the Senate. It was a master stroke of abolition policy; it united cupidity to fanaticism, and thereby made a combination which has swept the country. There were thousands of protectionists in Pennsylvania, New Jersey, New-York, and in New-England, who were not abolitionists. There were thousands of abolitionists who were free traders. The mongers brought them together upon a mutual surrender of their principles. The free-trade abolitionists became protectionists; the non-abolition protectionists became abolitionists. The result of this coalition was the infamous Morrill bill - the robber and the incendiary struck hands, and united in joint raid against the South. Thus stands the account between the North and the South. Under its ordinary and most favorable action, bounties and protection to every interest and every pursuit in the North, to the extent of at least fifty millions per annum, besides the expenditure of at least sixty millions out of every seventy of the public expenditure among them, thus making the treasury a perpetual fertilizing stream to them and their industry, and a suction-pump to drain away our substance and parch up our lands."
Here is another excerpt from it, and once again, slavery not tariffs is described as a Cause.
If you go about quoting the parts of it that pertain to slavery and not to the tariff, it should be of little surprise to anyone that the tariff issue is absent from your excerpt. I've already directed your attention to the paragraphs in it about the tariff, which you have since ignored on the grounds that it uses the synonyms "duties" and "protection," rather than "tariff," to describe the Morrill tariff act. I suppose it is a nice try from one who holds the embarrassing debating skills of Walt in high regards, but that kind of semantical nonsense simply will not fly around here without somebody calling you on it.