Thanks for a very interesting reply Carlos. I agree that lines on maps solve nothing at all mid- to long-term, but I confess the megaregion concept was one that interested me a very great deal, and the rationale of applying both economic and social support to cities to iron out inequality of opportunity and access seems both elegant and attractive.The thing with the US is that it's fairly close to the Swiss model. There are elections and propositions every flipping year. The smallest of positions (relatively, of course) all the way up to the highest ones are all elected offices.
There's the different levels starting with
City: mayors, councilmen and women, city court judges etc.
County: Board of supervisors, circuit judges, sheriff, tax collectors, school boards, utility districts etc.
State: Governor, Lieutenant Gov, AG, Insurance Commissioner, State representatives and State Senators, Judges.
Federal: Congressional and General elections.
All of these tiers of government can be both good and bad. Sometimes, it means that decisions at a local level can be made efficiently and effectively, but there will sometimes be extra clearance needed from the next tier up. The further up the tiers one goes, the more inefficient and ineffective the decisions appear - certainly to the average Joe Sixpack.
The division, or polarization as it's perceived has more to do with what is realistically a two party system. There are four sides:
-A bit of both (the floating voter)
The eleven nations described in the OP won't really address this. The divisions run right down the middle of towns and villages and megalopolises and country roads.
What happened this time last year was down to people being pissed off at the government. Imposition of new taxes, and fees, and mandates, with no perceived benefits, and folks losing full time jobs to part time ones or automation, leading to smaller paychecks and eventually anger, and a type of revolution which ultimately led to electing Trump.
The other suggestion made, that people of similar ideological persuasions would flock together, is a nonsense. People go where they can afford to go. Economics are what forces them together. No jobs in Skehana, move to Tuam. No jobs in Tuam, Galway. Galway - Dublin. Then on to foreign shores. Costs of living go up, but so do prospects, until eventually you find a place where you are comfortable and can afford to live and settle down.
Magical lines on a map won't create harmony or prosperity. Maybe they did in the past, but in the last forty years or so, the world has shrunk, and the lines have become increasingly blurred. The only ones that matter nowadays are the big regional ones.
Edit: apologies for a rather meandering post.