What we know about conditions in migrant detention centers

President Trump’s recent verbal attacks on Rep. Elijah Cummings, D-Md., were sparked by the congressman’s criticism of migrant facilities on the U.S.-Mexico border. The White House disputed Cummings’ characterizations. So what do we actually know about what’s going on in these detention centers? Judy Woodruff talks to the National Immigration Forum’s Ali Noorani about a “lack of transparency.”