The civil service commission is composed of three members who are registered voters of the city, appointed under this article. During their term members of the commission shall not hold any other office or position of employment with the city. Not more than two members shall be of the same political party, as determined by current voter registration, but members may have no party affiliation. The mayor shall appoint two members of the commission and council shall appoint one member of the commission. Each member of the commission shall serve a term of three years and until his or her successor has been appointed and qualified for office. The members of the commission shall be ineligible to be reappointed to succeed themselves for more than one additional three-year term, unless the member is completing a term for which he or she was appointed to fill a midterm vacancy.