A new lawsuit is fighting a federal law that gives preference to tribal families in the adoptions of Native American children. The Goldwater Institute filed a lawsuit against the U.S. Bureau of Indian Affairs Tuesday.

The lawsuit is on behalf of two children with some Native American heritage, now placed with non-native families. Goldwater Institute lawyer Clint Bolick said the families fear the Indian Child Welfare Act of 1978 could be used to deny permanent placement or remove the children.

"In Arizona, every child is entitled to a determination that a foster placement is in his or her best interests — every child, that is, except a child deemed to be Native American," he said. "In Arizona every child is entitled to the full constitutional rights of equal protection and due process of law — every child, that is, except a child deemed to be Native American."

Bolick said the law can be applied broadly, and that he wants it to be declared illegal and unenforceable. The law was passed nearly 40 years ago in response to large numbers of Native American children being removed from their homes.