A federal judge's ruling on Friday could lead to thousands more people joining a lawsuit over family separations at the U.S. border.
This is bad news for the Trump administration.
It was hoping that the separated families revealed in a recent watchdog report would not be allowed to join the suit.
That Health and Human Services inspector general report from January said thousands more children had been separated from their families than the government had disclosed.
The ACLU initially filed the lawsuit after the government separated a Congolese woman and her daughter last year, but it was expanded to include more families and is now a class-action suit.
Not long after that filing, a judge issued an injunction that blocked most family separations at the southern border and said the government had to reunite the families it had separated.
The lead attorney in the lawsuit responded to the news in a statement, saying, "The court made clear that potentially thousands of children's lives are at stake and that the Trump administration cannot simply ignore the devastation it has caused."