This is a rough transcript of a conversation involving my mother. A teacher at a college. The students involved are around 17 years old.
Student 1: You hear this? Gordon Brown is going to put a Tax on sweet wrappers and crisp packets to pay for the streets to be cleared!
Student 2: Seriously?! [ed – No really, seriously?] that’s awful.
Student 1: I know! I pay my road tax!
My Mum: Um… that’s not what road tax i… [interrupted]
Student 1: What I want to know is – if I’ve paid my road tax – why do I have to give way to pedestrians at Zebra Crossings. It’s my road.
My Mum: Road tax is there to maintain the roads. Pedestrians could walk there even if there was no road. You let people pass at Zebra crossing because that’s the etiquette of the road. Simple polite rules so everyone gets along, whether driver, pedestrian or cyclis… [interrupted]
Student 2: Don’t even get me started on cyclists. I just want to knock ’em down and kill ’em. They haven’t paid road tax!
My Mum: You shouldn’t kill people actu… [interrupted]
This happened. These people exist. They say these things like they’re good ideas.
My mother and I found the above hilarious and utterly chilling. Although Power 2010 think lowering the voting age to 16 is a good idea I have my reservations.
The usual arguments for universal suffrage amounts to a simple argument that although we are all different in property claims, intellectual capacity, religious adherence or appearance we all remain morally equal.
With the above rationale, there seems little reason to deny 16 year olds the vote. Few would argue that because of their age they lack a moral equivalence with people, say, twice their age.
People at 16 can join the army, they can work full time, pay tax and they can have sex (even if they can’t legally watch it). Perversely they can do all this without having a vote; deciding who we war against; what their tax is spent on and whether or not they can legally see boobies. 
The above college discussion doesn’t impact on the moral worth of the participants (cyclecide aside) so why shouldn’t 16 years olds have the vote?
The problem comes with the fact that it would be hard to find people who would argue that 16 year olds lack a moral equivalence with people half their age.
Democracy is not just an expression of common ideals, it is also a system of government. Government is, or should be, an enterprise to seek out the best institutions under which we should all live our lives.
Democracy is the meta-institution which offers us the best route to the best institutions on offer. This requires something more thoroughly selective than a simple moral equivalence, it requires an aptitude that few at 16 seem to possess.
Its prevalence at 18 can also seem somewhat lacking but this line must always be drawn slightly arbitrarily. This cleavage in society is unfortunate but necessary.
It may be that our educations system and civil society are particularly bad at equipping 16 year olds with the skills necessary, but unless it improves the enfranchisement of 16 year olds will only cause democracy to suffer.
Similar arguments were of course made in the past about women or black people and proved utterly incorrect. But unless 16 year olds can prove themselves more adept at mastering the basics they are going to have to remain outside the direct democratic process.
 Half of 16 year olds chief concern.