On March 16, 2005, Attorney General Mike Cox issued a formal opinion stating that the City of Kalamazoo's policy of providing same-sex domestic partner health insurance benefits to public employees for contracts did violate the amendment.

In May 2008, the Michigan Supreme Court held that the amendment bans not only same-sex marriage and civil unions, but also public employee domestic partnership benefits such as health insurance.

He wrote: "It is hard to argue with a straight face that the primary purpose—indeed, perhaps the sole purpose—of the statute is other than to deny health benefits to the same-sex partners of public employees.

Better in this instance, we think, to allow change through the customary political processes, in which the people, gay and straight alike, become the heroes of their own stories by meeting each other not as adversaries in a court system but as fellow citizens seeking to resolve a new social issue in a fair-minded way.

Oral arguments were held on April 28, 2015, and a ruling was made on June 26, 2015, allowing same-sex marriage in every state.