We have an inefficient costly system because people are pulling in two different directions and the power oscillation wastes years of productivity when power changes hands.
A phased separation with a scheduled timely vote for the union to continue on a per state basis. If the state doesn't have a simple majority vote to continue the relationship it is dissolved. Second if a simple majority of states in the union votes to remove a state they can.
From outside looking in: There's the perspective of Red States and Blue States, the conservative South and Liberal New England, the massive pull and difference between geographies; the popular HN participant who indicates "Every idea from California is bad because it's from California".
But when I zoom in to actual states, holly mackarel - most of them are something like 53 to 47 or 42 to 53. I don't think a single state broke into 70's. Freakin' Texas was 52/46. And from what I can tell (I'm not an election geek), a high difference is as likely to be a factor of small population as true segregation.
So splitting states doesn't seem like it'd accomplish anything except tyranny of small majority - the 50-something-percent imposing dominant will onto 40-something-percent of population; and/or the same issues that we now think of national will become, or be exposed, as state and local based.
That national politics - heck, politics at large - moves things to a somewhat centrist, mollassy, laggard middle, I'm starting to realize is a feature not a defect.
Edit: Now, if you were to separate rural vs urban, you might obtain more of a result that you want; that seems to be a far more consistent predictor of average values. Whether Blue or Red state (and same for Provinces here in Great White North), it's almost universally, strongly, obviously a rural vs urban difference, and than a matter of how much population lives in urban vs rural. Sure Texas is red, but Houston, Dalas, Austin etc are blue. But I don't think that's either feasible or would accomplish any positive goal whatsoever :)
The defensive advantages of a North American Empire make unity attractive in an easy to see manner. We have a lot more in common than we have to argue about; the only way we can think otherwise is by taking so much of our commonwealth for granted that we do not consider it when asking about modern Secession.
As much noise as red states like to make, many would probably still be hunter gatherers traversing the plains on their rutted dirt roads if not for the technologies and/or subsidies provided by their despised city dwelling "coastal elites."
(1)https://apnews.com/article/north-america-business-local-taxe...
That's why conservatives often believe pushing governance down to the lowest (most local) level possible. (Except when we want to use a higher level to make others do what we think best, but that's not an exclusively conservative behavior).