Obviously the point of this idea which will go nowhere is to exclude young people from voting, but a general "civics test" for voting would exclude much of the population if it was much harder than "Who is currently the president?"
I'm not saying 'yuk yuk Americans are dumb.' At a first pass it would exclude a lot of the population for the simple reason that any additional bureaucratic hurdle would. But on top of that, any non-ridiculously easy would fail lots of people. It is remarkably easy to blank on a basic knowledge test.
Costs to implement a federal test onto our glorious 50 states would be huge, also, too.
Anyway, this type of thing is too dumb to even argue with so I don't know why I'm bothering.