Even in foresight. It was a bunch of firebrands throwing a hissy fit, believing that the president would take their slaves when his position was only to keep slavery where it existed, seceding when it was the landed and wealthy elite that wanted to secede more than the common Southerner, trying to run a nation based on that elitist class system, which was also totally deficient in industry and infrastructure, lacking in urbanization compared to the North, and lacking severely in population, and all based on slavery, which was already increasingly a disdained issue. And to win, it was going to have to rely on getting Britain or France as allies; two nations which had long since banned slavery, and which were disgusted with the institution, and the only reason for aiding the CSA would have been to get cheap cotton and to cripple the United States. And they could and did move to getting cotton from their empires instead, so strike one, and government support for a slavery based state like the Confederacy would have lead to the outrage of the common population in those nations, so strike two. Not to mention it was a nation based on being against any government more official than the Articles of Confederation, which means it wasn't really much of a nation, and already had legitimacy issues since a government is based on it being declared the overall authority of a nation with some authority, and the CSA came into being by negating that authority in the United States and based itself upon it. Not to mention you'd have things like the governor of Alabama having to ask the governor of Georgia for shoes if they ran out, and there was no guarantee of the governor of Georgia agreeing to give help.
This does not make for a state that is going to work, which is my problem recently with CSA timelines since it more and more comes off like all it was ever going to be was an effort that was going to be doomed. This is stuff people could have seen coming. Had more moderate heads prevailed, the South probably would have gotten something it would have wanted. Slavery would have remained where it was, and continued for longer, likely being gradually phased out in the years thereafter, with the South not ravaged by war and destruction and shame, and probably with the slave holders paid or rewarded in some way to make up for their release of their slaves. Some of that's hindsight, but a lot of this is stuff people could have seen coming had idiocy not won the day.