Cut the urban areas into their own states (eg take the metro NYC or Chicago area and make them their own states) and then merge a lot of the "empty land" in between to try and equalize the population somewhat. End up with somewhere in the neighborhood of 15 urban states and 15 rural states.
I would slice it into something like:
* Appalachia Region
* Gulf Region
* Great Lakes Region
* Heartland region
* Rockies Region
* Cascadia Region
* Desert Region (Southwest US - need a better name but I'm coming up with a blank.)
* Maybe a Northern Shield region? Could just be part of the rockies region.
Those areas all have common environmental concerns and life experiences, and would bring a sufficient number of residents to be worth bothering over. Then you have the metro areas as their own states, enclaves within the larger regions. If metro areas grow out you would probably would have to have some mechanism to vote to transfer counties/districts between states.
Never going to happen of course, the number of political barriers is insane. And Republicans would never ratify any such plan that rearranged states as any sensible arrangement would unwind the disproportionate power they wield based on the current arrangement.
The only mechanism that could conceivably be achieved is splitting blue states up, and it's not really a good one since populations are so concentrated - imagine trying to split New York City into like 5 independent states, it would just be completely impossible to administer in practice.
In reality we will just keep bumbling along with our current system that immensely, disproportionately advantages the rural states and rural populations. Unless the country goes into an actual civil war, of course, which is not as unthinkable as it was 4 years ago.
