>>> Are there principles superior to the "principles of the Constitution"?
There should be no conflict between the "principles of the Constitution" and any that you might personally believe "superior".
If you see such a conflict, perhaps you should re-examine your concepts about both. -- I've heard that military Chaplin's are very good at explaining how duty to our country & Constitution can be reconciled with an individuals personal beliefs.
Were there Constitutional principles of liberty at odds with other "principles of the Constitution",
? -- That line is nonsense as you've written it, as principles cannot be at odds with each other.
the latter yielding " 'exceptional' property rights " of slave owners?
By accepting the peculiar institution as 'legal' under the Constitution, - the framers acknowledged that some humans did not have life & liberty, -- that they were property.. This was an exception to the rule.. Get it yet?
[not that you haven't all along, and are just belaboring the point]
I think the founders might have had different principles that yielded the Constitutional acceptance of slavery. The antislavery founders may have seen that the principle of a strong national self defense as superior to freedom for slaves. Given the choice of a larger and hence stronger nation vs a smaller and hence weaker nation, they chose the latter.
They judged that excluding the slave states would make the nation weaker, and chose the Constitutional principle of a strong national defense over, in this case, the conflicting Constitutional principle (that you see) that would have yielded freedom for the slaves.
The pro-slavery founders may have seen the Constitution as allowing the sovereign states to live by the "principle of slavery" that Henry Wise, Congressman (and future governor) from Virginia, spoke of sometime in the 1830's: "The principle of slavery is a leveling principle; it is friendly to equality. Break down slavery and you would with the same blow break down the great democratic principle of equality among men."
By accepting the peculiar institution as 'legal' under the Constitution, - the framers acknowledged that some humans did not have life & liberty, -- that they were property.. This was an exception to the rule.. Get it yet?
I don't get it yet. The founders had all kinds of exceptions to equality under the law and applied the law to various classes of humans in various ways. Examples: Minors, women, and men without property.