“It is a sordid business, this divvying us up by race.”

— Chief Justice John Roberts

Sordid, always. And sometimes lethal, as some Native American children could attest, were they not, like Declan Stewart and Laurynn Whiteshield, dead. They were victims of the Indian Child Welfare Act, which as construed and applied demonstrates how identity politics can leave a trail of broken bodies and broken hearts.

The 1978 act’s advocates say it is not about race but about the rights of sovereign tribes, as though that distinction is meaningful. The act empowers tribes to abort adoption proceedings, or even take children from foster homes, solely because the children have even a minuscule quantum of American Indian blood. Although, remember, this act is supposedly not about race.

The most recent case to reach the U.S. Supreme Court concerned a child who was 1.2 percent Cherokee. The Goldwater Institute, the Phoenix think tank whose litigators are challenging ICWA’s constitutionality, says “her nearest full-blooded Indian ancestor lived in the time of George Washington’s father.”

Children’s welfare, which is paramount under all 50 states’ laws, is sacrificed to abstractions like tribal “integrity” or “coherence.” The Goldwater litigators say guidelines from the U.S. Bureau of Indian Affairs tell courts that in determining foster care or adoption, “Placement in an Indian home is presumed to be in the child’s best interest.” ICWA forbids blocking placement in an Indian home because of poverty, substance abuse or “nonconforming social behavior.”

ICWA was passed to prevent a real abuse, the taking of Indian children from their homes without justifiable cause. But by protecting tribal sovereignty without stipulating the primary importance of protecting the best interests of the children, the rights of the tribes have essentially erased those of the children and the parents who wish to adopt them.

Declan Stewart was 5 when he was beaten to death by his mother’s live-in boyfriend. Declan had been removed from her by Oklahoma state officials in 2006, after his skull had been fractured and he received severe bruising between his testicles and rectum. But when the Cherokee Nation objected to his removal, Oklahoma, knowing how ICWA favors tribal rights, relented. Declan was murdered a month after being returned to his mother.

From age 9 months until she was almost 3, Laurynn Whiteshield and her twin sister were in the foster care of Jeanine Kersey-Russell, a Methodist minister in Bismarck, North Dakota. But when she tried to terminate the twins’ parents’ rights in order to adopt them, the Spirit Lake Sioux tribe invoked ICWA and the children were sent to the reservation and the custody of their grandfather. Thirty-seven days later, Laurynn died after being thrown down an embankment by her grandfather’s wife, who had a record of neglecting, endangering and abusing her own children. Laurynn’s sister was returned to Kersey-Russell.

Laura and Pete Lupo, of Lynden, Washington, raised Elle, who was less than 2 percent Cherokee and who came to them at age 14 months from a mother who was a drug addict and a father who was in prison. When Elle was 3, her uncle objected to the Lupos adopting her, and she was given to him.

By treating children, however attenuated or imaginary their Indian ancestry, as little trophies for tribal power, ICWA discourages adoptions by parents who see only children, not pawns of identity politics. The Goldwater Institute hopes to establish the right of Indian children to be treated as all other children are, rather than as subordinate to tribal rights.

“Is it one drop of blood that triggers all these extraordinary rights?” asked Chief Justice Roberts during oral arguments in a case involving ICWA. Indeed.

The most pernicious idea ever in general circulation in the United States is the “one-drop rule,” according to which persons whose ancestry includes any black or Indian admixture are assigned a black or Indian identity. In final adoption hearings in Arizona, a judge asks, “Does this child contain any Native American blood?” It is revolting that judicial proceedings in America can turn on questions about group rights deriving from “blood.”

It has been a protracted, serpentine path from Plessy v. Ferguson (1896) and “separate but equal” to today’s racial preferences. The nation still is stained by the sordid business of assigning group identities and rights. This is discordant with the inherent individualism of the nation’s foundational natural rights tradition, which is incompatible with ICWA. It should be overturned or revised before more bodies and hearts are broken.

George Will’s email address is georgewill@washpost.com.