(CNN) A federal judge in California ruled Wednesday that a challenge to the practice of separating parents seeking asylum from children at the border can proceed.
The ACLU brought the case against the Trump administration.
In his opinion, the Judge Dana Sabraw said "at a minimum, the facts alleged are sufficient to show the government conduct at issue 'shocks the conscience' and violates Plaintiffs' constitutional right to family integrity. Accordingly, Defendants' motion to dismiss Plaintiffs' due process claim is denied."
The ruling is a victory for critics of the administration's separation of families — though plenty of hurdles remain before the practice is outlawed.
The ruling does not mean the challenge will ultimately succeed — but it is a substantial step for critics of any separating families who say the practice is abhorrent enough that it should be unconstitutional in any case. The judge's ruling Wednesday keeps that argument alive.
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In a statement, the ACLU lauded the decision of the court to allow the motion for a nationwide preliminary injunction to proceed.
The ACLU brought the case initially on behalf of a Congolese woman seeking asylum in the US who was separated from her 7-year-old daughter for months.
After the court proceedings began, a DNA test confirmed the girl was her daughter, and Homeland Security Secretary Kirstjen Nielsen told Congress that the lengthy separation of the two "took too long." She said at the time families are only separated in the interests of the child.
But since that testimony, the issue has taken on additional intensity after the Department of Homeland Security announced it would refer every adult caught crossing the border illegally for prosecution — meaning any families will thus be separated, even if they are pursuing legal asylum.
The ACLU argued in court that even if they accept that the prosecutions are legal, which they reserve the right to challenge later, that families are not being reunited after the few days that adults spend facing their misdemeanor charges — and that is a violation of their rights.
The government had sought to dismiss the case, in part because the woman, who is listed in court papers as "Mrs. L," has been since reunited with her daughter.
The judge did dismiss some of the claims in the case. She rejected two procedural, statutory challenges to the practice of separating families that ACLU had also brought, noting in part there is no specific law that mandates that the government do so nor is the policy of prosecuting border crossers a formal rule.
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But the challenge to the constitutionality in general of parents being subjected to prolonged separation from their children was allowed to proceed.
This story has been updated.
CORRECTION: This story has been updated to correct a reference to the gender of Judge Dana Sabraw.