Your opinion on the Supreme Court's decision does not invalidate it. Unilateral secession as practiced by the southern states was illegal and not sanctioned by the Constitution.
Surely you jest! Have you nver heard of a Supreme Court reversing itself, or of an Amendment that overturned a Supreme Court decision? Or of one Amendment overturning another earlier one? Think about it.
Sure I have. And none of those things have happened where unilateral secession is concerned.
Nowhere in the Supremacy clause does it state that judicial decisions are supreme. Seccession WAS not illegal, the was no prohibition against it, the federal government has not been delegated the power to prohibit secession, either via legislation or by court judgements.
The TvW was a specious piece of bovine excrement, the holding that a Texas was still a state negated the decision on the bonds.