You have to research the political movements prior to 1860 all the way back to the ratification of the U.S. Constitution to understand party platform formations and stances. It is a very complicated story of the growth of "the right of slavery expansion" and the abolitionist movements. The term "fire-eater, and who it represents, is very important and should not be ignored in trying to understand their cause....disunion. They, the fire-eaters tried many different political causes to use to move people to vote or support disunion. So did the abolitionist, who's primary platform was disunion and the removal of the U.S. Constitution as the federal law. Both, by 1850, had adopted pro-slavery and anti-slavery causes to gain political support to cause the disunion of the United States.

Disunion and the right of secession by any state was taught as legal truth in most universities and schools in the United States right up to 1860. Many judges wrote of it, using the example of how individual States seceded from the Articles of Confederation to form the new United States under the then new Constitution. They wrote that there were two Federal Government running at the same time until the other States were forced to join the new government under threat of economic ruin.

From this start the movement for disunion began. Many causes were thrown up as excuses to break up the union; i.e. wars, taxes, laws, territorial gains, and finally slavery.

The fire-eaters ran the 1st period of secessions prior to Lincoln's planned attacks on the forts, but they were politically pushed from power during the creation and ratification of the new Confederate Constitution. None, or very few, that I know of, were in any Executive positions during the war and, other than blocking attempts to allow Black Confederates into Confederate service, didn't have much power in directing the war. After Fort Sumter, the secession movement and the war efforts were taken over by States Rights and Southern Independence advocates...the idea of "secession for the protection and expansion of slavery" lost political popularity quickly to "secession against Northern aggression and a dysfunctional United States".