RIO GRANDE CITY, TX - DECEMBER 07:  A one-year-old from El Salvador clings to his mother after she turned themselves in to Border Patrol agents on December 7, 2015 near Rio Grande City, Texas. They had just illegally crossed the U.S.-Mexico border into Texas. The mother said she brought her son on the 24-day journey from El Salvador to escape violence in the Central American country. The number of migrant families and unaccompanied minors has again surged in recent months, even as the total number of illegal crossings nationwide has gone down over the previous year.  (Photo by John Moore/Getty Images)