In this March 30, 2021, photo, young migrants wait to be tested for COVID-19 at the Donna Department of Homeland Security holding facility, the main detention center for unaccompanied children in the Rio Grande Valley, in Donna, Texas. U.S. officials are scrambling to handle a dramatic spike in children crossing the U.S.-Mexico border alone. (AP Photo/Dario Lopez-Mills, Pool, File) (Dario Lopez-Mills/AP)