There’s really not a lot of of discussion of foreign trade in the documents the states ratified to enact secession. [0] They sure do talk about slavery quite explicitly though.
[0] - https://www.battlefields.org/learn/primary-sources/declarati...
[0] - https://www.battlefields.org/learn/primary-sources/declarati...
Because tariffs are a congressional matter, not a state matter. They were trying to justify secession via the states' rights angle. Also, politicians don't like using money as a justification for their actions. It comes off tacky. They want to appear noble and virtuous. Sorta like how nobody invaded iraq for oil. You invade iraq for democracy. Just like the american independence was about "liberty and freedom" not tariffs and the right to steal native land west of the appalachian mountains. "Liberty and freedom" by slave owners. Using your logic, the iraq war was about democracy and the american independence was about freedom. Do you believe russia is invading ukraine to free ukraine from nazis too?
Fictitious WMD, even more fictitious ties to al-Qaeda (and because, as distinct from North Korea, as described by then -Deputy Secretary of Defense Paul Wolfowitz, Iraq “floats on a sea of oil“, notionally foreclosing leverage for non-military pressure against those fictions.) “Democracy” and “freedom” weren't cited as the reasons for going in, but as things we needed to assure in the aftermath of destroying the existing regime for other reasons. (And then later as “wins” that retroactively justified the invasion even if there never were WMD to protect against.)
How goddamn stupid is anyone to believe that shit?
I think that's what he means.