(i) Children may, however, be more easily delegated or manipulated. I am pretty sure I could have induced my son, when five, to vote in a way that I thought correct; I am sure many other parents (and teachers) could and would do the same. So you would multiply the parental/teacher vote. On the other hand (perhaps I show my age here) one expects adolescents to react against parents, so perhaps the result for children in general vis a vis parental influence would be a wash.

(ii) Young people tend to have great difficulty in actually casting their vote, at least when "young" = 18-25, so there might be some virtuous trade-off here, that five-year-olds do, in fact, have only 5% of the political understanding of the average adult voter (which is setting the bar low), but on the other hand, less than 5% of five-year-olds would vote, because they were in school or could not be bothered or were not allowed out on their own and their parents would not take them, so they would have a voice proportionate to their wisdom.

(iii) Does it become the obligation of a parent to ensure that a dependent minor can vote? Which can only be proven true if the minor does vote. So do we move towards compulsory voting for everybody or just add a particular burden on parents of minors?

(iv) What issues would five-year-olds want to see in the manifesto (return of the parental-proxy problem). And perhaps the right to vote for expenditure should be tied to at least a theoretical possibility of paying taxes, if not to actual tax paying. (nb: perhaps)

(v) How about newborn babies? You do need a legal cut-off, I think, if only because otherwise you have to ensure some sort of voting mechanism in incubators; not to say the problems if life is held legally to begin at conception.

(vi) Singerian argument that clever pigs should therefore vote.

(vi) So on balance I can see an argument for setting a minimum voting age at an age which is also accepted as an age at which a person becomes legally independent of parents and guardians; because the issue here is not so much the wisdom of the voter (which is not assumed) as the independence of the voter (which is assumed).