There's nothing false in what I said.
They asserted their right to secede under the 9th and 10th amendments.
How stupid was that?! I mean, who would be foolish enough to stand up and say (straight-faced of course) "I assert my right that is undefined anywhere but my own brain!"
The fact is that some (few) claimed this loophole but, unlike the bozos who claim that you don't have to file federal income taxes, few actually put it to the test.
The southern slavers were indeed just that foolish. As a consequence they lost a shite-load of citizens, and a huge fortune. As a direct consequence there is now a SCOTUS ruling that prohibits secession unless through mutual accord.
Completely false. All powers not granted to the federal government are reserved by the states. Since nowhere in the US constitution is the power to prevent secession by a member state granted to the federal government, that is one of the powers reserved by the states.
The express resolutions of the two most important and biggest states at the time of ratification amply demonstrates that that was the original intent of the states when they ratified the constitution.
These were the same states which had unilaterally seceded from the British Empire 8 years earlier.