Thanks for the thorough analysis! Your further points and examples on the Federalism within Federalism and State Representation sections are very interesting.

Noting your opposition to dividing states more along rural/urban lines, I would like to address some of the points you make on that issue.

Whilst city states are usually highly dependent on trade, this does not preclude their independence, and many have been very successful both historically and in the modern day. This dependence on trade does make them more vulnerable to certain adverse international events such as blockades, but by being part of a federation that does not have these vulnerabilities, a state is shielded from this concern. This “safety in numbers/diversity” is what a lot of the point of political unions ultimately is.

That rural areas are often subsidised by more urban ones is true, but it is fairly standard for a federal government to address this issue by allocating funding between states appropriately, subsidising poorer states without micromanaging their governance, which allows the state government to deal with the specifics of their situation. By having states that contain a wide range of environments, you are forcing states to allocate funding between these environments, whilst also managing the spending of this funding. This risks underfunding of certain areas (either city or country), due to the majority of the population belonging to the other group, or even if the funding is allocated fairly, it risks “ivory tower” decision making by political elites that represent the majority but are uninformed about the minority issues.

I think the shifting of power to the federal government is independent from this question – as you mention, it is a problem that is occurring in Australia and Canada, both of which have states that are highly mixed between urban and rural, much like the US. I completely agree that this is a problem, and the point you describe about the federal government effectively forcing states not to make major reforms as otherwise they would lose certain federal funds is a huge issue. I just don’t think this has anything to do with the states ability to self-sustain or their urban/rural mix. After all, it is happening regardless.

Regarding externalities, most of the issues you raise boil down to the idea that combined planning/development policy is beneficial. I don’t disagree that it is – infrastructure that crosses state lines and policies that deal well with migration to or from cities is an important thing to have. The issue is, that I’m not convinced a state that is a mixture of a huge metropolis and a large area of sparsely populated farmland will actually do this (I mean, they seem like they’re currently doing a pretty bad job in most places). By splitting these populations between different states, both get governments which can negotiate with each other to advocate for their residents.

Rather than a state with a majority of metropolitan residents railroading through legislation that is to the detriment of rural residents (California) or the opposite (Texas), you would have a negotiation in which the wishes of both groups were put forth by people that actually represented them. If no agreement could be reached on a particular issue, each state can still do what is within its power to do what is best for its residents, whereas in a single state, you would either get political deadlock in which nothing could be done to the benefit of either group, or you would again have one group with an absolute majority doing things at the others expense.

The lack of examples of successful “rural states” is less that there are none, and more because this is the norm. By “rural states”, this is referring to states that do not contain any metropolis that is large enough to be a state in its own right. It depends on what you decide this cut-off is, but if we say that a state-worthy metropolis is one that has a CSA population over 4 million, most US states would be “rural”. With the exception of California (LA & SF), New York & New Jersey (NYC), Illinois (Chicago), Maryland & Virginia (DC metro), Texas (Houston & DFW), Pennsylvania (Philadelphia), Florida (Miami & Orlando), Massachusetts (Boston), Arizona (Phoenix), Michigan (Detroit), Washington (Seattle), Minnesota (Minneapolis) and Georgia (Atlanta), most US states don’t contain a city large enough, which leaves 35/50 states. Looking at this: https://wallethub.com/edu/states-most-least-dependent-on-the-federal-government/2700/ it would appear that Kansas, Iowa and Nebraska all do pretty well for themselves and are fairly convincingly rural.

Likewise, many countries fit this description – successful countries comparable in population to Singapore & Hong Kong are Ireland, New Zealand, Denmark, Norway, Finland, Sweden, Austria and Panama. The populations of the largest metropolis in each of these countries compared to their total population ranges from 23% (Sweden) to 36% (Panama), so their largest city is neither dominant enough to make up the majority of the country’s population, nor sufficiently large to warrant statehood in its own right. Even if you were to remove the largest city from each, you would still be left with several other cities in each country (Bergen, Malmö, Cork, etc.) that would be capable of driving their economy.

I very much understand your concerns about the erosion of states’ autonomy, and the growing role of federal government. I would however argue that enabling very different and potentially specialised states to come together in a way that allows them to maintain that specialism without having to worry about complete independence in every possible sphere (food, energy, defence, etc.) is most of the entire point of federalism. If a state is going to forgo the advantages of being able to both specialise and allow its specialism to be effectively politically represented, whilst being maximally adversarial with the federal government, it may as well not be in a federation at all!

In all seriousness though – I think one of the main issues that I see with the US government is its lack of representativeness, and that may be one of the drivers of this erosion. Anything that makes politicians more representative of their constituents is likely to improve perceptions and engagement. The more different states are in character, the more important it is that the federal government leave them alone to get on with their own affairs. A disengaged populace that reside in states that all contain a paralysis inducing blend of very different interests is going to find it easier to sleepwalk into the federal government running everything than an engaged populace that reside in states that stand for coherent and consistent policies.