Secretary of State John Kerry took a shot at Donald Trump during his Friday commencement speech at Northeastern University, by saying no wall is big enough to keep dangerous terrorists out of the United States. "Many of you were in elementary school when you learned the toughest lesson of all on 9/11," he said. "There are no walls big enough to stop people from anywhere, tens of thousands of miles away, who are determined to take their own lives while they target others." "So I think that everything that we've lived and learn tells us that we will never come...