It would be exceedingly difficult to judge which 16 year-olds should be allowed to vote just as it would be exceedingly difficult to judge which 18 year-old (or 38 year-olds, for that matter) should be allowed to vote. In a real sense, voting is a right that needs to be given to everyone over a certain arbitrary age because it is simply impossible to objectively say who deserves to be allowed to vote.
That said, if we have to come up with questions to ask, we might ask some of the following questions.
- Do you think that the US should intervene in other countries when we feel that those countries have governments that are doing bad things to their people?
- What role do you think that the government should play in making sure that there is not too much of a difference in wealth between the richest and the poorest Americans?
- What sorts of things can the government reasonably do to try to improve our country?
As you can see, there are no knowledge-based questions here. I do not ask people to name four rights from the Bill of Rights or to explain how a presidential veto can be overridden. I think that the best way to determine who gets to vote (in this scenario) is to see who has thoughts about government and society. This is much more important than who knows what. Voters can always learn the facts. What is more important is that they should care enough to have thought about certain fundamental issues that face our country.