Texas Attorney General Ken Paxton will likely challenge a federal appeals court ruling that upheld the Indian Child Welfare Act, a U.S. law that gives preference to tribal members for adoptions and child placements, a spokesman said Monday.


Paxton had joined several non-Native American families in a legal effort to overturn the 1978 law, arguing that its preferences amounted to race-based restrictions that discriminate against non-American Indians and deny some children access to loving homes.


Opponents of the law won an initial victory last year when a federal judge in Fort Worth ruled that it improperly gave preferential treatment to Native Americans based on race and violated the 10th Amendment by requiring states to implement federal policy.


But after the federal government and four tribes appealed, the 5th U.S. Circuit Court of Appeals on Friday upheld the constitutionality of the law, which was enacted after Congress identified “alarmingly high” numbers of Native American children who were forcibly removed from their families for adoption and foster care by non-Native Americans.


The law, commonly known as ICWA, defined “Indian child” based on the federal government’s political relationship with American Indians and tribes, not race, the appeals court said.


“We conclude that the special treatment ICWA affords Indian children is rationally tied to Congress’s fulfillment of its unique obligation toward Indian nations and its stated purpose of protecting the best interests of Indian children and promoting the stability and security of Indian tribes,” Judge James Dennis wrote for the court’s three-judge panel.


The appeals court also rejected arguments that the law improperly infringed on state powers.


According to the ruling, Judge Priscilla Owen, a panel member, plans to file a partial dissenting opinion soon.


For children who cannot be placed with family members, the federal law gives preference to placement with other members of their tribe, followed by members of any federally recognized American Indian tribe.


Leaders of tribes that intervened in the case to defend the law — the Cherokee Nation, Oneida Nation, Quinault Indian Nation and Morongo Band of Mission Indians — praised the appeals court for rescuing a law that they say serves the best interests of children.


“We are pleased that the court followed decades of legal precedent in its ruling, preserving a law that protects Indian children and allows them to retain their identity by staying within their families and tribal communities,” the leaders said in written statement.


The lawsuit challenging ICWA was originally filed by three non-Native American families, including one from Texas, whose adoptions were thwarted or complicated by the law.


Paxton — who joined their lawsuit along with officials from Indiana and Louisiana — argued that the law created a “separate and unequal system” that can work against a child’s best interests by thwarting a state law that requires children to be placed in the most loving and stable families possible.


Marc Rylander, a spokesman for Paxton, said the appeals court failed to provide justification “for the federal government preventing Texas law from putting the interests of children first.”


“While we are still reviewing the opinion, we anticipate seeking further appellate review of the important issues raised by this case,” Rylander said Monday.