Commentary The federal Indian Child Welfare Act (ICWA) is a classic instance of congressional overreach: It imposes sweeping child adoption rules on the states and has caused extreme hardship for Native children and the non-Native families who have opened their hearts and homes to those children. The Supreme Court has agreed to review whether the ICWA is constitutional. There are four consolidated cases under the title of Haaland v. Brackeen. Those challenging the law raise several constitutional issues. They claim the ICWA’s treatment of Indian children violates the 14th Amendment’s Equal Protection Clause. They also say the law “commandeers” state agencies—i.e., directly orders those agencies to do certain things, thereby violating the 10th Amendment. The challengers further question a constitutional theory long popular among the legal elite. That theory holds that the federal government has absolute (“plenary”) power over the Indian tribes, without regard to the reserved powers of the …