It is a flat out lie to claim the 10th supports secession. It does not and never did. What it refers to is the police power within the individual states though it could be argued that it also obliquely sanctifies slavery.
There is not one word on secession in the Constitutional Convention. NOT ONE.
Since the Articles of Confederation maintained the Union was perpetual and the Constitution strove to create "a more perfect Union" and never changed the Articles stance on indivisibility, it is utterly illogical or deceitful to claim that the right to secede was there.
If the AoC was "perpetual", why did the several states abandon it? Why did the states form a new government if the old one was permanent? Why not include the word "perpetual" in the Constitution if it too, was to be permanent?
It was just as "perpetual" as the AoC was.