Their had been no declaration either by convention, legislative action or public vote when Confederate troops were welcomed into their state. (None of those methods would have been legitimate BTW.)
The point is, they had accepted 'foreign troops' on their soil while they were still part of the United States. That is of course assuming they accepted the Montgomery government of Jefferson Davis as a legitimate nation. The rub with that is under the Constitution, they had no authority to recognize foreign governments.
So did they really believe in unilateral secession, or were they just playing legalistic games?
You know the answer. At least be honest about it.
Only if you assume that a plebiscite was somehow required to authorize secession.
Care to cite some references? (BTW, it will be extremely entertaining to see you trying to justify 'the right of State secession via plebiscite'... ;>)
So what you are saying appears to be that State secession was completely Constitutional, but these folks screwed up the paper work.
Congratulations.
You know the answer. At least be honest about it.
I will be completely honest about it - perhaps you should consider that position as well:
...the principle on which all our political systems are founded, which is, that the people have in all cases, a right to determine how they will be governed.
William Rawle, 1829