I have a piece on CNN today about whether we should follow Scotland and let 16-year-olds and 17-year-olds vote. It’s a subversive piece. It’s easy to read it as advocating that we expand the franchise, but I’m underhandedly getting people to see that their arguments against letting high schoolers vote apply just as well to against letting many other people vote.

The key argument against letting high school juniors vote is simple: Their choice would affect all of us. After all, a voter chooses for everyone, not just him or herself. Many worry that most 16-year-olds lack the wisdom or knowledge to cast smart votes, so we don’t let them vote because we want to protect ourselves from their decisions.

And this concern is often grounded in reality — young adults are indeed in many cases profoundly ignorant about politics…

So far, so good. But:

As political scientists Michael X. Delli Carpini and Scott Keeter noted in their 1996 book, “What Americans Don’t Know About Politics and Why It Matters,” political knowledge is not evenly spread among all groups. Membership in some demographic groups correlates with high levels of political knowledge, depending on region, income and education, while other groups tend to correlate with political ignorance.

So, this is the catch: If you wanted to exclude 16- and 17-year-olds on the grounds that they are more likely to be ignorant or misinformed, you would also in effect be arguing against other demographics having a say.

They edited out specific information about which groups. Care to guess which demographic groups (based on age, race, sex, income, location, etc.) tend to have low information?

What about letting all the kids who can pass the civics exam vote?

And what should we do if we still can’t get over our fear that 16-year-olds are too dumb to vote? Well, we needn’t exclude all of them. Instead, we could allow any child who can pass the U.S. citizenship exam to acquire the right to vote.

Of course, if you think that’s a reasonable standard for a 16-year-old to have to meet, it’s worth remembering that most voting-age adults cannot meet it either. So why should we demand more from our teenagers than we expect from ourselves?