Noting is ever truly settled. Once any part of the Constituion is cast aside by the ones currently in power for their own goals, they can not force all others to abide the sections of the Constitution as they chose.
That is solely the reason war was initiated against the seceding Confederate States, to FORCE them to agree to rule benefiting the northern States.
In the Civil War the north held the majority of industrial power whereas the South was primarily agriculrtural and even to a large degree “subsistance” agricultural. Such war now by the so called Blue States against seceding States would not have a similar result simply because the actual balance of power. In 1860 the north would not have tried enforcing their say had the industrial power been equal.
Of course now there may be some chance nobama would attempt to enlist the aid of our sworn enemies such as Putin and the Arabs (I do not mention the UN as they have never shown much aptitude at successful war, being more or less low paid and poorly lead mercenaries), but again the balance of power would be with the seceding citizens who were inspired by the goal of their true and just freedom, not conscripted and short of nuclear attack against the so called Red States, those international interlopers would not prevail as the north almost did not prevail in 1864.
Noting = Nothing...