It's okay, there's already a system for testing literacy in intending voters. We just need to revive it.

[Just5minswithDacre]

For everyone who seems to think that qualified electoral registration would be a good idea.

http://www.crmvet.org/info/lithome.htm

Another angle

http://www.slate.com/blogs/thevault/2013/06/28/votingrightsandthesupremecourttheimpossibleliteracytest_louisiana.html

Wow. Where are the "people are too thick to vote" crew?