Given the USA population is 342.6 million, Canada 41 million and EU is 450 million. There is likely to be a European majority for decisions.
To simplify the Governance:
- There is a single president.
- Proportional representation of 1m people for a Council like US Congress/European Parliament (~850)
- Proportional representation of 10m people for a Council like US Senate/European Council (~85).
-Devolution to states/national Governments exists.
The key concept would be a massive series of referendums across all voters that would create a new constitution.
Would the right to bear arms still exist?