Please explain what you mean. The Tenth Amendment was/is part of the US Constitution. It applied/applies to all states in the Union. Explain to me how it doesn't apply to the right of a state to secede.
Pardon me for paraphrasing the late Justice Scalia of the SCOTUS, as I don’t have the text at hand (I’m not anywhere near my library.).
Justice Scalia said that when the AWI was won that our Founders weren’t at all sure what sort of new nation that the United Colonies (We were not yet the USA.) would be and that NONE of the 13 new States would have entered into any compact of the States freely that they couldn’t just as freely depart “at their own motion”. At that time, NOBODY actually knew whether the new USA would be a workable system of government or it would prove to be a miserable failure. = That is ONE of the options for dealing with a tyrannical central government & an option that is short of a civil war or another revolution.
For example, if this year the citizens of California voted to leave the USA, they are FREE to do so & the only options for the other 49 States is allow CA’s secession to occur peacefully OR to chose to go to war to stop the former US State of California’s secession.
(In 2019, the thought of California, given their current state of LEFTIST lunacy, leaving the USA forever makes me smile.)
Yours, TMN78247