Teams of lawyers at the Department of Homeland Security, Health and Human Services, and the Justice Department spent today analysing the ruling and how the Administration intends to respond. A Justice Department spokesman declined to say whether the agency will appeal.
Sabraw's ruling is the latest complication in a controversy that has already proved politically perilous for US President Donald Trump, who last week issued an Executive Order ending the forced-separation policy, replacing it with indefinite family detention.
Still, about 2000 children remain split from their parents. The government had urged Sabraw not to grant the nationwide injunction, saying Trump's order, which followed days of bipartisan outcry, had resolved the concerns animating the suit.
The court said it did not.
Instead it found that the zero-tolerance policy, begun in early May, with the Executive Order and a subsequent fact sheet issued by the Department of Homeland Security outlining the process of removal, marked a sharp departure from "measured and ordered governance, which is central to the concept of due process enshrined in our Constitution."
It faulted the Trump Administration for "a chaotic circumstance of the Government's own making."
The judge stated bluntly: "The unfortunate reality is that under the present system, migrant children are not accounted for with the same efficiency and accuracy as property."
A Justice Department spokesman said that the decision "makes it even more imperative that Congress finally act to give federal law enforcement the ability to simultaneously enforce the law and keep families together."
The spokesman added: "Without this action by Congress, lawlessness at the border will continue, which will only lead to predictable results - more heroin and fentanyl pushed by Mexican cartels plaguing our communities, a surge in MS-13 gang members, and an increase in the number of human trafficking prosecutions."
In his 24-page order, Sabraw ruled children could be separated at the border only if adults with them were found to pose a danger to the children. He also said adults could not be deported from the country without their children.
Sabraw, 59, was nominated to the federal bench by President George W. Bush in 2003.
The initial plaintiffs in the lawsuit were a mother and her 6-year-old daughter, split up after arriving in the United States in search of sanctuary from persecution in Congo.
They arrived at the San Diego border in November, the suit alleges, at which point the "frantically screaming" child was taken to a facility in Chicago, while her mother, identified only as "Ms. L," filed for asylum in California.
The pair were reunited in March, but the civil liberties group persisted with claims by other migrants.
