A federal judge sided with the Trump administration against the American Civil Liberties Union in a lawsuit challenging their power to separate families at the U.S.-Mexico border.

U.S. District Judge Dana Sabraw issued a lengthy 26-page decision saying that the administration was not abusing the power of the executive branch, according to the Associated Press.

"It is an invitation that is potentially massive in scope," Sabraw wrote, "invades an area that is particularly within the province of the executive branch to secure the nation's border, and goes beyond this court's class certification and preliminary injunction orders, which were focused on the administration's practice of separating families at the border for the purpose of deterring immigration, and failing to reunify those families."

The ruling applies to family separation at the border due to the administration finding the parents to be unfit or dangerous. It applies to about 900 children who were separated under such criteria.

Sabraw did give the ACLU a partial victory by rejecting the government's argument that 90-minute DNA tests to determine parental disputes were operationally difficult.

"The court strongly reaffirmed that the Trump administration bears the burden if it attempts to separate families based on an accusation that the adult is not the child's parent," said attorney Lee Gelernt, who represented the ACLU.

"We are evaluating the decision to determine next steps on how to ensure that children are not separated from their parents based on minor infractions," he added.

Family separations at the border have become a contentious issue, with critics claiming the administration is acting with malice and cruelty to deter illegal entries, while supporters say the separations are necessary and not unique to the Trump era.

Here's a previous report about border separations: