Now, I'm not a student of politics, so I may be making some error, but I'd say (1) only about 2/3 of the ones on that list* are in a decent political position, and (2) that in any event a shifting of the balance of power between states (not just US states, any states) and their corresponding federal government is a big deal and not to be done lightly.
Of course, because I'm not a student of politics, I also don't take any strong position about what the USA should or shouldn't do with DC. If y'all turn DC into Trump's personal walled castle and themed gold-plated golf course, all I'm gonna do is get some popcorn, I won't stop you.
* including e.g. the one I live in, where the president has far less power than in the American system and real power is with the chancellor, and also the voting system is completely different and supports a plurality of parties not just two: https://en.wikipedia.org/wiki/Mixed-member_proportional_repr...
Just to clarify: I meant the fact that the capital of a country needs some kind of special exception. That normally really isn't the case.
NL is kind of special: the capital of the country is Amsterdam, but the seat of government is the Hague. But in Belgium, which is about as divided as it comes, the seat of government is Brussels, which is itself bi-lingual.
I don't think this is a problem that requires a particularly convoluted solution. What it does require is for people to simply play by the rule of law. And that's the thing that the United States is currently putting to the test on every metric that matters.
