May be the euroweenies could use the federal government system that work for us for over 120 years until we changed it with the 17th Amendment: a lower house of representatives who are elected in local districts every 2 years, 2 senators per country that are elected by their respective country's Parliament every 6 years, and a directly elected president with a term of 4 years with a maximum of 2 terms.
What on earth have you people got against popular election of senators rather than naked auctions in which special interests combine and conspire in the corruption of state legislative poohbahs to PURCHASE US Senate seats to serve "the interests." It is bad enough under our Seventeenth Amendment system were the bribery is less direct and would be intolerable under the previous system.
And, NO, state governments have NO "rights" vis-a-vis their own citizens. Another ludicrous concept. "States' rights" are vis-a-vis the federal tyrants and SCOTUS in particular not against the voters.
Are you trying to formalize "government of the "interests," by the "interests," ad for the "interests?"
Instead, the EU (until sensibly abolished ASAP) should try actual FREEDOM for those poor souls unfortunate enough to bear its yoke.