The major lightning rod is the tariffs and not slavery.
I'm afraid period southern politicians would disagree strongly on that.
For example, Alexander Stephens.
"[FONT=Verdana, Arial, Helvetica, sans-serif][SIZE=-1]Our new government is founded upon exactly the opposite idea; its foundations are laid, its corner- stone rests, upon the great truth that the negro is not equal to the white man; that slavery—subordination to the superior race—is his natural and normal condition. This, our new government, is the first, in the history of the world, based upon this great physical, philosophical, and moral truth."
The Alabama Ordinance of Secession refers to the states that wanted to secede as 'slaveholding". So does the Texas Ordinance of Secession. And Virginia.
The Georgia Declaration of Causes of Secession refers to their political opposition as 'non-slave-holding' states, the Republican Party as an '[/SIZE][/FONT]an anti-slavery party[FONT=Verdana, Arial, Helvetica, sans-serif][SIZE=-1]', and complained of '[/SIZE][/FONT]the rise, progress, and policy of anti-slavery'.
[FONT=Verdana, Arial, Helvetica, sans-serif][SIZE=-1]The Mississippi Declaration of Causes of Secession states '[/SIZE][/FONT]Our position is thoroughly identified with the institution of slavery'.
[FONT=Verdana, Arial, Helvetica, sans-serif][SIZE=-1]The South Carolina Declaration of Causes of Secession, refers to its political allies as '[/SIZE][/FONT]the other slaveholding States' and its political opponents as 'the non-slaveholding States'.
[FONT=Verdana, Arial, Helvetica, sans-serif][SIZE=-1]The Texas Declaration of Causes of Secession says Texas' '[/SIZE][/FONT]institutions and geographical position established the strongest ties between her and other slave-holding States' and to their political opposition as 'the non-slave-holding States'.
They don't call themselves the 'anti-tariff' States and their opposition the 'pro-tariff' states.