IMO voting should be mandatory for everyone eligible.. even if it's "none of the above" or "don't give a fook"
At least that way there is a recorded proper representation of what people think as a whole. At the moment a party can get "voted" in with a 'majority' that is smaller than the number of people that didn't vote at all, implying that they aren't in fact the ones that the true majority of people want!
