They had something like that in the Jim Crow era of the South - Literacy test. Struck down as anti-Black which it was but it was also anti-Red Neck illiterate white since everyone had to take it. (Which has conveniently been forgotten!) Of course it effected blacks disproportionately so it had to go!
You know, I would care which subgroups it affected as long as it produced a more informed electorate.