6.3 What size of majority vote should decide the issue?

In many types of democratic vote, a bare majority (technically, 50 per cent +1) is enough to decide outcomes. But often constitutional changes – changes which would affect the basic structures or political rules of the game – are regarded as needing ‘supermajorities’ of, say, 60 or 70 per cent. A basic change in the sovereign political unit would certainly count as a constitutional change. If the Bs get to vote, we might be concerned if only a bare majority favoured secession, especially if the voting turnout was low. Because the Cs form a minority within the B community, should we look for a majority of Cs as well? In addition, the turnout might be a special issue for such significant constitutional changes.