Persons who are not able to understand the ballot do not wish or attempt to vote. Election judges also protect against voting abuse. Jury commissions and the courts are able to excuse persons who are not able to serve on a jury. The voters are the ultimate judges of who is qualified to hold elective office. The language in the constitution is obsolete and offensive in view of these protections.
Persons are generally under guardianship because they have mental limitations.
Therefore, they are not capable of making the sound decisions required to vote, serve as a juror or hold public office. People involved in court may not want their cases decided by a juror who is under guardianship. Persons under guardianship may be unduly influenced by their guardian, resulting in distortion of the voting process. One person may actually be given two votes if the guardian directs the actions of someone who is not capable of acting independently. Not all people with limitations are willing or able to acknowledge those limitations.