@danalan there are 13 Federal districts. I think there should be a Justice for each one.
@Lindy
The problem is, at some point we need to add more states; if there eventually are 27 federal districts, the number of justices becomes unmanageable.
At some point we'll figure out that global challenges require global government; and begin selling democracy rather than bombing potential clients into submission.
We should have been adding states all along. There should be hundreds of states by now.
I think we (the US) as a true melting pot, have both the best chance, and in fact a duty; to bring about world peace and harmony.
Nationalism, racism, sexism, and religion are the enemies of this goal - and you describe nationalism pretty well.