Exactly, but how much of our history is word playing? Was Slavery the cause of the War of Northern Aggression or not? Certainly it was a part. But It was NOT the cause. In my opinion there were much greater issues at stake than Slavery or Taxes/Tariffs. Issues which men were willing to fight for. Such as the ability to live ones life as he see fit under the laws of the land, Liberty its called.
The southern states saw the politic events as a threat to their liberty. The fight to maintain political power between factions in Congress with the 1820 Missouri compromise and the debates and events of those times was the bedrock of the unrest. Morality of slavery was not the issue of importance except as a power play.
Each state had the right and the ability to abolish slavery within their borders. No state had the right to dictate policy of another under the Constitution. That was called States Rights. The 9th and 10th Amendments. Although it was not practiced, the State of New Hampshire did not outlaw slavery in that state until 1858. Those were the safeguards from an authoritarian central government run by unelected officials.
In short the War was caused over the interpretation of the Constitution. The political powers that were in play to change the accepted interpretation of the rights of states. And the perceived threats to force compliance by use of the military to blockade Charleston Harbor with Major Robert Anderson and Fort Sumpter December 1860. The "Star of the West" incident January 1861, and the attempt to reinforce that blockade by the federal government in April 1861, were the tipping points of the southern states deciding to seek their own Independence, and form their own Government as the 13 Colonies did in 1776 from England.