I don't really agree with your perception of what the current state of affairs would be without the federal government, nor the ideology behind the founding of

I don't really agree with your perception of what the current state of affairs would be without the federal government, nor the ideology behind the founding of the US. However, that's tangential to the important point - which you do indirectly hit on. The swap from a state based system to a federal based system most fundamentally changes the scope of operation. Good things, such as the direct termination of slavery, can affect the entire nation at once. On the other hand, this power also comes with an equal but opposite negative. In that bad things can now also affect the entire nation at once. So for instance not that long ago in the past we were enforcing eugenics from federal level down. In the famous supreme court case Buck vs Bell, where the US federal government ruled in favor of eugenics, supreme court justice Oliver Wendell Holmes famously said, "We have seen more than once that the public welfare may call upon the best citizens for their lives. It would be strange if it could not call upon those who already sap the strength of the State for these lesser sacrifices, often not felt to be such by those concerned, in order to prevent our being swamped with incompetence. It is better for all the world if, instead of waiting to execute degenerate offspring for crime or to let them starve for their imbecility, society can prevent those who are manifestly unfit from continuing their kind. The principle that sustains compulsory vaccination is broad enough to cover cutting the Fallopian tubes. Three generations of imbeciles are enough.". Interestingly enough that ruling has never actually been overturned. The reason that eugenics fell out of fashion lay largely with a certain German enthusiast. If not for him it's not unreasonable to imagine the federal level dystopia that we were starting to consider going down. When things are enacted at the state level this gives people the option of getting away from the insanity. When things happen at the top, leaving your country is usually not a practical option. And so too for the question I was responding to. Should it be legal for foreigners to vote in US elections? Maybe, maybe not. It would probably depend heavily on the state in question. But thanks to our system, that question can no longer be answered by states. In 1996 the federal government made it illegal at the national level.