Okay. I don't agree that it was bound to happen, but I suppose it is possible that a slight tariff hike could have been done with minimal controversy. This was not the case of what happened though.
Had Southerners really wanted to block tariff increases that they regarded as excessive, they could have used the Senate rules of the time to filibuster the tariff bill.
Strategically that is entirely possible to push off the tariff, but for indefinate sustainability across four years it is simply not practical or realistic. The cards were heavily stacked against any limited effort that could be mounted in the Senate.
The macroeconomic effects were less clear and less discussed. High tariffs diminish trade and make competing industrial countries less prosperous. But the question for early 19th century America was whether they would simply be exporters of raw materials and importers of finished goods from Britain, the economic powerhouse of the time, or develop their own industries. The desire to use tariffs to promote manufactures at home was understandable.
Carlander and Majewski address an ignored aspect of the problem. Confederate tariff rates were lower, but would be applied to a larger percentage of goods, since the South had so few industries. Therefore, this lower tariff would have had a protective effect and inhibit trade, given the wide volume of goods that would have to be examined and taxed, until the South were able to develop its own industries. Because so many products and such a large percentage of goods would be taxed, the dichotomy of the protectionist North and free trade South isn't as clear cut as one might think. Virginia manufacturers were quite happy with the lower tariff, because they recognized that it would make Northern manufactures less competitive.
It's also intriguing that it was not Lincoln, but Buchanan, who would have gone far to preserve the peace, who signed the Morrill tariff.