The first threats of Secession were from the New England states and my condemnation of them would have been just as scathing as of the Southern ones. It would have been just as unconstitutional there as south of the Mason-Dixon line.
No one ever pretended the 10th allowed dissolution of the Union until the fireeaters of the South in the 1850s. Such a "right" was as non-existent as a "right" to healthcare or affordable housing or food.
Every single Founder as well as Jefferson loathed the idea of secession and thought it madness exemplified. He even mentioned its advocates in his first inaugural address as objects for ridicule. Madison told Hamilton explicitly that once in the Union forever in the Union. Jackson was ready to hang South Carolina's agitators proposing secession. Washington's Farewell Address (written by Hamilton) was a warning not to follow those urging secession. There was not ONE word at the CC supporting the concept. Thus, NONE of our great leaders supported the idea that it was a "right" left to the states. That discovery was left to the quacks and charletans 70 yrs later.
Actually Madison himself spoke of secession during the CC, and expressed a desire for state militia officers to be appointed by federal authorities to help prevent secession. He lost.