Lorella Praeli speaking to reporters at the White House in Dec. 2014. Praeli, who arrived in the U.S. as an undocumented immigrant, is now a top official in Hillary Clinton's presidential campaign.
Children line up in the cafeteria at the Karnes County Residential Center, a temporary home for women and children detained at the border, in Karnes City, Texas, in this Sept. 2014 photo.
People line up to cross into the U.S. from Mexicali, Mexico in this 2012 photo. A new report finds the flow has tended to go the other way since the recession, with more Mexicans leaving the United States than arriving.