Why is it 18? Up until the 70's, 21 was common. Sometimes higher. So why is 18 the magic age until which it is acceptable to disenfranchise you?
Note that the argument that someone younger doesn't really understand the consequences of their actions etc. - whether right or wrong - is severely diminished by a representative system where the candidates must be older, combined with a system where, if, say, the voting age is lowered to 16, the 16 and 17 year olds are extremely unlikely to skew the results so much that the candidates elected end up being someone that isn't also believed to be suitable by a large percentage of 18+ voters. So the potential "damage" if 16 and 17 year olds all decide to vote completely and utterly irrationally is quite limited.
But unless there is concrete evidence that 16 and 17 year olds objectively will make substantially less informed choices in an election than other groups we let vote, why is it any more acceptable to disenfranchise a 16 year old than it was to disenfranchise 18 year olds? Or blacks? Or people who didn't own land?
The burden of proof should be on those who wants the limit set higher to justify, with evidence, why specific groups needs to be/remain disenfranchised.
The major source of political pressure behind the 26th amendment (and, yes, nationally lowering the voting age for all elections takes a Constitutional amendment) was that 18 was the age of conscription and, well, Vietnam.
Why is it more acceptable to disenfranchise 15 year olds than 16 year olds? Would your logic lead to all citizens being allowed to vote, including 1 day old babies? If not, why?
Did I say it was? I argued for 16 on the basis of this comment thread.
All countries have constraints based on mental competency. The point is that a typical 16 year old (and yes, probably 15 year olds too) are well above the mental capacity where we still allow adults to vote.
The current age limits are not justified with any evidence of that the group is substantially less competent to make the relevant choices than many other subsets of the population that we don't hesitate to allow to vote. If someone for example started arguing for iq tests, or a test on knowledge of current affairs, it would be exceedingly hard to put the barrier low enough to not exclude any enfranchised adults, and you'd almost certainly end up including children well below the age of 16 (e.g. political youth parties in many countries have a lower age of 14, some even lower, and you'll find people in those organisations that are schooled in political science beyond what most adults ever will be).
This would not extend to 1 day old babies because a 1 day old baby lack the ability to make any kind of informed choice. In fact, a 1 day old baby lack the physical ability to observe the alternatives and indicate a choice. They would be excluded by any kind of mental competency standard.
Where exactly to draw the line would be hard, but expect it to drop substantially over time, as it already has.
Note that the argument that someone younger doesn't really understand the consequences of their actions etc. - whether right or wrong - is severely diminished by a representative system where the candidates must be older, combined with a system where, if, say, the voting age is lowered to 16, the 16 and 17 year olds are extremely unlikely to skew the results so much that the candidates elected end up being someone that isn't also believed to be suitable by a large percentage of 18+ voters. So the potential "damage" if 16 and 17 year olds all decide to vote completely and utterly irrationally is quite limited.
But unless there is concrete evidence that 16 and 17 year olds objectively will make substantially less informed choices in an election than other groups we let vote, why is it any more acceptable to disenfranchise a 16 year old than it was to disenfranchise 18 year olds? Or blacks? Or people who didn't own land?
The burden of proof should be on those who wants the limit set higher to justify, with evidence, why specific groups needs to be/remain disenfranchised.