I'll just use the same as the authors of the Constitution....oh, they didn't use some single "foundational principle" as a universal litmus test for their work....well then, must not be required of all men, just some.
In all seriousness, the Socratic Method can be so drawn out...but since it is so much fun......Let's see, ...
What significant non-monarchial governments have endured and functioned well based upon one single foundational principle? Please list them.
Inasmuch as I cannot point to ANY government at all, which has endured and functioned well... I guess I'd have to say no.
Are you suggesting that the lack of a predicate is sufficient reason to dismiss a governmental form?