In Michigan, they had some kind of referendum against affirmative action, which is making the higher ed people crazy because their side lost, so they filed suit in federal court to overturn the state law referendum, and got "the other side" (presumably, the same side, as the case was in effect part of state government suing the state government) to stipulate to the issuance of a preliminary injunction by the District Court against the implementation of the new law. A real person intervened, and on his appeal, the Sixth Circuit reversed the issuance of the preliminary injunction.
The opinion says the preliminary injunction was improper because the University had no chance of winning on the merits.
In one memorable phrase, the Court says: "One does not generally think of the First Amendment as protecting the State from the people but the other way around—of the Amendment protecting individuals from the State." Regarding the Supreme Court's recent rulings on affirmative action, the Court says: "Grutter never said, or even hinted, that state universities must do what they barely may do."
Finally, the Court observes: "this is an unusual way to use the federal courts. Ordinarily, one might wonder why a court would hesitate to delay the implementation of a state law for six months when the State's Governor, the State's Attorney General and its Universities stand together in urging its suspension. That is particularly so when they offer reasonable administrative grounds for the delay—uncertainty about how the law will be interpreted and uncertainty about applying it during this year's enrollment cycle. Yet none of those administrative grounds explains why the federal courts should delay the law's implementation on federal grounds."
Perhaps the reason why the University chose not to file in state court is because the lawyers suspected that they would lose on appeal before the Republican-majority Michigan Supreme Court - unless some party opposite associates Jeffrey Fieger into the case.