Mich. Comp. Laws § 37.1204: Labor organization; prohibited conduct.

Sec. 204.

A labor organization shall not:

Exclude or expel from membership, or otherwise discriminate against a member or applicant for membership because of a disability that is unrelated to the individual's ability to perform the duties of a particular job or position which entitles the individual to membership.

Limit, segregate, or classify membership, or applicants for membership, or classify or fail or refuse to refer for employment an individual in a way which would deprive or tend to deprive an individual of employment opportunities, or which would limit employment opportunities or otherwise adversely affect the status of an employee or of an applicant for employment, because of a disability that is unrelated to the individual's ability to perform the duties of a particular job or position.

Cause or attempt to cause an employer to violate this article.

Fail to fairly and adequately represent a member in a grievance process because of the member's disability.