The campaign slogan was never "One Person One Vote" or even "One Adult One Vote" but always "One Man One Vote". Most people think that their countries had a functioning democracy even before the vote was extended to women - everyone knows Switzerland got there last (in 1971). Of those who fought and died in the trenches of the First World War, very few believed in female suffrage.
There were other, lesser anomalies which eventually got removed: in the UK, the Property Owner's Vote and the Universities Vote which gave some people two votes. Those were only abolished in 1948.
Some adults don't get the vote - in the UK, prisoners, and in other times and places, lunatics and bankrupts. No one in politics suggests that children should have the vote, though in my life time the voting age has been reduced from 21 to 18 and for the Scottish independence referendum it has been reduced to 16.
So Universal Suffrage is a bit variable at the edges but the fundamental principle, if there is one, is a bit like that of Mutually Assured Destruction - you vote Conservative and I vote Labour and we can cancel each other out. But if there are 51 of you and only 50 of us, you win. And in the British system at least, Winner Takes All.
It's relevant that in most cases, major things we associate with democracy, like a free press and freedom from arbitrary arrest, were in place before the arrival of universal suffrage. Think only of the Swiss case. In ex-colonial and other liberated countries where universal suffrage has been introduced first, a free press and so on do not always follow: universal suffrage on its own does not make a democracy.
All the history of the fight for what was also called "Manhood Suffrage" took place against a very particular demographic background, a world of young people and working people. Life expectancies in the major democracies meant that the elderly - the retired, pensioners, the elderly frail - were a small part of the population. The significance of this fact has generally been overlooked. It gave a forward-looking bias to democratic politics, sometimes disastrous for democracy itself (Fascism, Nazism).
Now the situation has changed and the increasingly elderly demographic of the advanced democracies, and even more so of active voters, gives a backward-looking bias to their politics. British political parties lack a vision for the future because they are not responding to voters who are seeking such a vision. They are responding to voters who want the past and whose time horizon is the next few years.
There is no obvious reason why this situation should be accepted. We generally treat it as natural that children should not have the vote - we don't think of them as disenfranchised. However, Googling to Wikipedia on Plural Voting, I discover that it has sometimes been proposed that parents should get extra votes for dependent children, in order to increase the importance of long-term planning as an election issue. The idea was put forward by the UK think tank Demos in 2003, by the Dutch economist Lans Bovenberg in 2007 and it is an official policy of the Christian Party of Austria.
In addition or as an alternative, I suggest we should think about whether elderly people should have the vote or the full vote. Maybe the vote is something you should get at 18 and keep until you are 68 or, subject to fitness,78 or 88. A bit like a Driving Licence. Maybe it is something which should reduce in value as the decades pass, so that a full vote at 18 becomes a half vote at 68 and so on down.
It's not an outrageous idea. It's about securing a future. And if Scotland goes, England will be in dire need of some future-oriented thinking. And it ain't gonna get it in Clacton (see my previous Blog post)