Can you give me the criteria for being 'fair'? To me, the vote seems fair because it was the conditions to form the USA, and the USA has had centuries to chang

Can you give me the criteria for being 'fair'? To me, the vote seems fair because it was the conditions to form the USA, and the USA has had centuries to change it but has chosen not to. At least, it is as fair as a vote that requires 'citizenship' to count, given that lack of citizenship doesn't stop one form being directly impacted by the decisions of the President.