I suppose it just troubles me slightly when I look at those around me soon to reach voting age and think, "wow - can you put that bottle/joint/other teenager down for two minutes to get yourself educated enough to make a sensible and informed decision about the future of our country?" Unless you choose to take politics in school (which, hilariously enough, is only usually available once you are in further education, which in itself is optional) or spend time researching into it, you're not going to get enough of an idea of how a country is run in order to make decisions about which government and policies to go for.
Unless you are someone who has an interest in politics and makes a point of carefully paying attention to everything during the run-up to election day...I dunno. Politics seems to be synonymous with boredom to a lot of young people and my overall concern is that they grow up to either not care, not vote because they think it's pointless or else be told by other people who they should vote for - which is the worst option, IMO.
It's difficult to put an age limit on voting, in my view, because no matter what, you are going to get morons with the right to a say in how the country is run. I was sent a link to a video the other day by someone in their 80's - it was one of those done by Nick van Riel (google him if you really want to know who he is and what he stands for) and whilst a lot of what was being said was true factually, it was presented in a very almost-Nazi-esque kind of way...it actually made me feel rather uncomfortable and I wasn't quite sure what to make of it afterwards. But it portrayed a lot of what many in Britain are currently feeling about immigration, taxes, muslims etc. And it's these people who have the right to vote and could potentially get a group like the BNP in power. It's come close before and many of the voters are those whose parents vote the same way, or all their peer group vote - rarely does it seem to be the result of careful consideration and information from all sides.
I know there's a degree of spin to be expected - it's politics, after all - but I'm thinking we ought to spend at least some time educating the future generations about the different government groups, policies, what agendas really mean, a bit of political history etc. I mean, there are so many people who have refused to vote conservative because of what Margaret Thatcher did to the working classes back in the 80's. No one is telling them of the good things she did, just the mining stuff, taking away school milk, selling off housing to the private sector. Maybe it isn't even something that can be taught objectively enough? I don't know...