[Non-Sequitur]

Because prospective decisions are clearly identified as such in the opinion. Since the majority opinion in Texas v. White clearly states that the Texas ordinance of secession was without basis in law and therefore null, then it is clearly not a prospective decision.

[Aurelius]

"Since the majority opinion in Texas v. White clearly states that the Texas ordinance of secession was without basis in law and therefore null, then it is clearly not a prospective decision."

That is hardly an accurate representation of the majority opinion. The opinion was based on the extra-Constitutional doctrine of the perpetual and indissoluble nature of the federal union which was in turn based on the absurd Lincolnian dogma that the federal union preceded the Constitution and was older than the states. Whatever the standing of the decision, its foundation is crap.