For all of Donald Trump's tough talk on Mexico on the campaign trail, few concrete moves to secure the United States' southern border have materialized in the first 100 days of his presidency. This is partly because of the inherent limitations of the office; to even begin trying to turn the ambitious pledge of building a border wall into a reality, the president would have to first secure the funding from Congress. So far, though, lawmakers have been reluctant to release any money for the project. Yet while Trump's vision of a wall has been too impractical to implement, there is one statistic the president can point to as a win on border security. ...