Mich. Comp. Laws § 51.353

Sec. 3. No person shall be appointed a member of the commission who is not a citizen of the United States and an elector of the county for a period of at least 3 years immediately preceding his appointment. No commissioner shall hold any other elective office, place or position under the United States, state of Michigan, or any city, county or other political subdivision thereof; nor shall any commissioner serve on any political committee or take any active part in the management of any political campaign. Not more than 2 of the commissioners, at any one time, shall be adherents of the same political party.