The landmark law governing adoptions of American Indian children, designed to keep them within Indian families, has been struck down as unconstitutional by a federal judge in Texas.

In an Oct. 4 ruling that has stunned Indian rights advocates, U.S. District Judge Reed O'Connor found that the Indian Child Welfare Act of 1978 illegally gives Indian families preferential treatment in adoption proceedings for Indian children based on race, in violation of the Fifth Amendment's equal protection guarantee.

Additionally, he ruled that the law violated the 10th Amendment's federalism guarantees, specifically the so-called "anti-commandeering" principle established by the Supreme Court, which bars Congress from "commanding" states to modify their laws. In this case, O'Connor found that the ICWA "offends the structure of the Constitution," since it requires state courts to implement a policy "unequivocally dictated" by the federal government. The same doctrine has been used by at least two federal courts, in Pennsylvania and California, to block the Trump administration's crackdown on so-called "sanctuary cities."

The ruling is a victory in the eyes of state attorneys general in Texas, Louisiana and Indiana, who argued the Indian Child Welfare Act imposed a "discriminatory framework" against nonnative adoptive parents. But in the eyes of Indian rights attorneys, the ruling is destructive.

They fear it may not only jeopardize Indian children, who are far more susceptible to being removed from their families than nonnative children, data have shown. They fear the ruling, if upheld, may also jeopardize decades of legal precedent affecting tribal sovereignty, said Dan Lewerenz and Erin Dougherty Lynch, attorneys with the Native American Rights Fund.

"The decision is jarring, and not just for its effect on ICWA," Lewerenz said, "but because as far as I know this is the first time ever that a federal statute enacted to benefit Indians has been found to be unconstitutional on the grounds of equal protection. It introduces perhaps an entirely new world of Indian law. And we worry that this might be what the plaintiffs intend, that this is not just an effort to undermine ICWA, but to undermine all Indian law."

The case at issue stems from a Texas couple's efforts to adopt a baby whose biological parents are from the Cherokee and Navajo tribes. The couple, Chad and Jennifer Brackeen, fostered the baby from the time he was 10 months old until he was 2. At that time the Brackeens sought to adopt him with the support of the baby's biological parents.

But a family court thwarted their plans, blocking the adoption on the grounds of the Indian Child Welfare Act. The family sued in October 2017. The couple later successfully petitioned the court for the adoption, but the lawsuit challenging ICWA continued. The Cherokee Nation and several others intervened as defendants.

The law does not bar non-Indian families from adopting or fostering Indian children outright. But in order for a nonnative family to succeed, they have to show "good cause" that the child can't or shouldn't be adopted by American Indians.

The protections were enacted for good reason, said Sarah Kastelic, executive director of the National Indian Child Welfare Association. At the time ICWA was drafted, Indian children were being taken from their families at astonishing rates, a systemic problem that reflected a continuation of decades of assimilation efforts, Kastelic said.

The Welfare Act strengthened native parental rights and, in the event that a child had to be removed, mandated that courts first consider the child's extended family, followed by another member of the child's tribe, then members of other tribes.

The main dispute in the lawsuit boiled down to whether this preferential treatment was based on race or instead based on the child's political affiliation with the tribe as a citizen. O'Connor ruled that it is a "race-based" statute — an interpretation that the federal government and tribes disputed.