They should have required a "double majority" - both a "Leave" majority nationally, and a "Leave" majority in at least three out of the four constituent countri

They should have required a "double majority" - both a "Leave" majority nationally, and a "Leave" majority in at least three out of the four constituent countries. Then "Leave" would have failed. Obviously, they should have announced this rule before having the referendum. There is precedent for this - Australia uses effectively the same criteria for constitutional amendments (both a majority nationally and a majority in the majority of states). Although, unlike Australia, the UK doesn't have a written constitution, and isn't formally a federation (although devolution has given it quasifederal features), the UK definitely needs something like that given the extreme lopsidedness of its population (one of its four members, England, being roughly 80% of the total