I second Brandioch: the "citizens" proviso is a loophole wide enough to drive the Exxon Valdez through. If the regime is unwilling to extend "rule of law" to non-citizens--or if it's willing to rescind the privileges of citizenship for its own nationals, who may be deemed "enemy combatants" by executive fiat and killed out of hand (as in Yemen the other month) without oversight or appeal, the "enemy combatant" determination being made retroactively--then "rule of law" doesn't mean very much.
The American citizens in this forum were all of us born into the arrangement: none of us signed the Constitution (which I do regard as a damned fine piece of work overall, although I suspect that many of the signatories would keel over could they but see the powers this King George and his predecessors of the past couple of generations have asserted), but we are nominally bound by its provisions, even if our masters are obliged only to pay it lip service.
I'd submit that "consent of the governed" is an important element in the legitimacy of a regime, and that ours has gone by degrees from "consent" to "acquiescence" to "apathy" with regard to the attitude of the governed. Face it: for all of our lives this country has been transforming itself by fits and starts into a police state (I'm subject to drug testing at work [although, weirdly, in the fifteen years since the policy was implemented the moving finger has always passed me by], something Stalin himself never demanded of his slaves), and the process has been on afterburners these past fifteen months.
"legitimate regimes?" We in this country have no right to talk about these after the 2000 Selection.
cordially,