That's a supreme court ruling, not the Consitution. And what else would you call the civil war besides a revolution?
This seems to be the pertinent part of the decision"When, therefore, Texas became one of the United States, she entered into an indissoluble relation. All the obligations of perpetual union, and all the guaranties of republican government in the Union, attached at once to the State. The act which consummated her admission into the Union was something more than a compact; it was the incorporation of a new member into the political body. And it was final. The union between Texas and the other States was as complete, as perpetual, and as indissoluble as the union between the original States. There was no place for reconsideration or revocation, except through revolution or through consent of the States."
That sets some very interesting angles to what the civil war was. And it sets some very chicken and egg arguments up. And it comes from a post civil war mindset of the collective being it's own entity beyond the states that make it up. Under that belief each state could walk away, without "consent of the states" and the "United States" federal entity would still exist.
To me it argues as if the secession of the confederacy was irrelevant. There is this "perpetual entity" that is completely severed from the members. A kind of "you can take Texas out of the United States, but not the United States out of Texas"
