Here is where I answered the question the first time on this blog.
I am not someone who advocates monarchy as the best form of government for all peoples at all times. Just as I do not advocate "democracy" as the best form of government for all peoples at all times. (Nor would I claim that democracy is the only legitimate form of government.)
Contemporary Jacobites, supporters of the Stuarts, are quaint, and I am guessing they take seriously the claim of Duke Francis of Bavaria to the throne of England. However, they do take seriously a certain view of the role of the monarchy and the origin of its authority.
I follow Aristotle in advocating rule by the one divinely virtuous man who surpasses all others (monarchy) or by a group (aristocracy--the number of which tends to be small, given the scarcity of real virtue) or by many, in the case of a polity. The first two are ideal, but the constitution which is best suited for a particular people will depend on the historical circumstances, customs, and so on. Who is qualified to rule? The virtuous. Any constitution that deviates from that is, well, a deviation. Can we really say that the virtuous rule in our country? And do current arrangements allow for the virtuous to assume office? Or is "the process" manipulated by other powers. (What those powers may be I will leave unidentified.)
The form of government does not concern me as much as the size of the community. The modern nation-state has the same problems due to size as a real empire. "Empire" is often associated with expansion and the subjugation of peoples not sharing the same language and/or culture. Here I use empire to refer to a political community of vast size and population.
I should read what Max Weber has to say about bureaucracy; I am familiar with MacIntyre's comments in After Virtue. While empire is not new, it seems to me that the degree of centralization of power in European nation-states may be, as they were able to make use of certain technological advancements improving communication.
I have not read much about the Persian Empire; micromanagement was not a feature of the Chinese empire--much power was delegated to the provincial governors and magistrate-officials at the county level. iirc, the same was true of the Roman Empire. There was more exercise of subsidiarity in those two historical entities than is now here in the United States? Why? Because, among other things, we have enabled corporations and individuals to amass great economic power across state lines, and to ruin local economies, which is necessary for self-sufficient political communities, and hence autonomy. How? By giving corporations (legal) personhood and powers associated therewith--and a near-absolute right to accumulate property and wealth. It might be possible to give an association some form of legal personhood but limited 'rights'--ultimately its our basic understanding of justice that determines what the possible outcomes will be.
The other side is the accumulation of power by the Federal government.
Btw, we don't have a real polity [~democracy] here in the United States, not as Aristotle defined it. All the talk about us having the "ideal" Aristotelian or Thomistic mixed constitution is mostly nonsense.
I don't foresee much improvement happening through government, state or Federal--if anything the present crisis should make it clear to us that our priority is to witness to Christ in our own lives, to bring others to Him, and to exercise charity in all things (which includes doing what we can to protect and foster the local community).
References to the 28 August issue of American Conservative, "What is Left? What is Right? Doest it Matter?" are popping all over the place on paleoconservative blogs--I'll add another. Clink on the link to see individual articles, or go here for all of them.
*A discussion of personhood here. It is ok, but I would not accept everything in there, especially the attempt to distinguish moral personhood from natural personhood.