When the Sixth Circuit struck down Michigan’s anti-affirmative-action Proposal 2 in 2012, its reasoning may have left some observers hunting for their Fourteenth Amendment treatises. Rather than applying conventional equal protection doctrine, the court rested its decision on an obscure branch of equal protection jurisprudence known as the Hunter doctrine, which originated over forty years ago. The doctrine, only used twice by the Supreme Court to invalidate a law since its creation, purports to protect the political-process rights of minorities by letting courts invalidate laws that work nonneutrally to make it more difficult for them to “achieve legislation that is in their interest.” The Sixth Circuit’s decision created a clean circuit s...