As explained here:
In 1997, the Clinton administration entered into a settlement agreement in Flores v. Reno, a lawsuit filed in federal court in California by pro-illegal immigration advocacy groups challenging the detention of juvenile aliens taken into custody by the Immigration and Naturalization Service.
The Clinton administration agreed to settle this litigation despite the fact the Supreme Court had upheld the Immigration and Naturalization Service regulation that provided for the release of minors only to their parents, close relatives, or legal guardians.
According to the Department of Homeland Security, the Flores agreement allows the agency to detain unaccompanied minors for only “20 days before releasing them to the Department of Health and Human Services which places the minors in foster or shelter situations until they locate a sponsor.”
But in a controversial decision, the U.S. Court of Appeals for the 9th Circuit, the most liberal in the country, has interpreted the settlement agreement to apply to “both minors who are accompanied and unaccompanied by their parents.”
In other words,it is the 9th Circuit’s misinterpretation of the Clinton administration’s settlement agreement that doesn’t allow juvenile aliens to stay with their parents who have been detained for unlawful entry into the country.
Of course, if those parents would simply agree to return to their home countries, they would be immediately reunited with their children. So those who come here illegally are themselves to blame for their children being assigned to foster care or to another family member or sponsor who may be in the country.
The executive order signed by President Donald Trump directs the attorney general to file a request with the federal court in the Flores case to modify the settlement agreement to allow the government “to detain alien families together throughout the pendency of criminal proceedings for improper entry or any removal or other immigration proceedings.”
Of course, the administration’s critics know about this settlement and know it limits the ability of the administration to keep alien families together.