Here's the opinion (PDF). Excerpt:
[Washington v. Seattle Sch. Dist. No. 1, 458 U.S. 457 (1982), and Hunter v. Erickson, 393 U.S. 385 (1969),] expounded the rule that an enactment deprives minority groups of equal protection of the laws when it: (1) has a racial focus, targeting a goal or program that “inures primarily to the benefit of the minority”; and (2) works a reallocation of political power or reordering of the decisionmaking process that places “special burdens” on a minority group’s ability to achieve its goals through that process...I thought the "diversity" interest counted as compelling in Grutter was for the educational benefit of all of the students in the classroom. Under Grutter and Gratz, an interest in benefiting the minority would not support the state's choice to have affirmative action, so how can it work as the basis for saying that the state can't choose not to have it? The Seattle and Hunter cases are a bit strange, and I would not be surprised if the Supreme Court took this case and not only reversed but reframed the doctrine.
Proposal 2, like Initiative 350, has a “racial focus,” because the Michigan universities’ affirmative-action programs “inure primarily to the benefit of the minority, and [are] designed for that purpose,” for the reasons articulated by the Court in Seattle. Just as the desegregative busing programs at issue in Seattle were designed to improve racial minorities’ representation at many public schools, race-conscious admissions policies increase racial minorities’ representation at institutions of higher education, see, e.g., Grutter, 539 U.S. at 316, 328-33 (describing the University of Michigan Law School’s minority-student-enrollment aims); Gratz, 539 U.S. at 253-56 (describing admissions policies at the University of Michigan regarding underrepresented minority groups).