I propose that the massiveness is not spatial. It is ideological. Draw a straight dividing line in ideology space, and you can cleanly cleave US society. Project it onto a map, and it looks like a fuzzy boundary between urban and rural. But I think it's clear that the partisanship is generated by ideology and has reflections in geography, rather than the other way around.
So consider federalism that isn't based on states/territories of land, but rather based on ideological space. If we used a Proportional Representation system, I might have some ideological representatives in congress. As it stands, my representatives represent their party and my physical location, but not the thoughts and ideas of voters like me.
One could hope that the system would tend towards overall liberalism, but IME with the EU it's the opposite.
Over recent years, we have got mandatory registration of SIM cards right as an influential neighbor state did the same (official explanation by our government: because of terrorism threat, which is essentially nonexistent here), EU-wide ban on many useful chemicals which have been used in terror attack mostly in Britain and France, and I'm hearing that the Swiss (a Schengen member) are having their own problems with the EU over firearm regulations, even if they aren't an EU state.
This is a massive problem for federalism, something that is cherished heavily here in Canada too as our provinces can each be quite different and autonomy is defended quite strongly in debates (at least historically).
But it always seems to continually centralize more and more.
I feel like this is one of the biggest driving forces for partisanship in a massive country like the US. Of course you can’t achieve cohesion across such a massive country. It’s much easier for smaller states.
That’s also why it bothers me when people point to tiny European countries like Scandinavia as examples of how the entire US should be. Nothing scales that easy.
There needs to be some clearly defined things that are federal (natsec that is entirely external, currency, healthcare insurance gov monopoly, trade pacts along logical trade routes - something India is dying for where apparently Trucks transporting goods need to stop at each local powerblock with paperwork/taxes and it’s slows everything to a grind, etc).
You can see the downsides of centralization in things like the drug war clashing with states who want to legalize or decriminalize. Clearly this should be up to the states. And many more things too.
Instead there are countless US federal agencies doing who knows what. I’ve heard some huge numbers.
And the push politically always seems to more and more power not only federally but more dangerously in the executive branch (which we saw a massive rise in during the post 9/11 Bush years and continued in Obama’s term).
We need a rebirth of federalism globally and a push back against everything going federal and centralized. Especially with populations continually growing.