It was the retained right of the state in question to make that determination, as New York had written, 'the powers of government may be reassumed by the people whensoever it shall become necessary to their happiness'. It was their call.
And further, you see it applying to all states even though it has no force of law even in New York?
Well I guess we had to keep Masser happy and he was powerful unhappy about the ol Black Lincoln fellow being elected, so by the powers vested in them by the people of New York state, Texas could seceed.
Man, that makes splended constitutional logic. < / sarcasm >