1) Family separation is wicked. It is harmful to kids and absolutely should NOT be the default U.S. policy. Americans are better than this.
2) This bad new policy is a reaction against a bad old policy. The old policy was “catch-and-release.” Under catch-and-release, if someone made it to the border and claimed asylum (whether true or not, and most of the time it wasn’t true), they were released into the U.S. until a future hearing date. Many folks obviously don’t show up at these hearings, so this became a new pathway into the U.S.
3) Catch-and-release – combined with inefficient deportation and other ineffective policies – created a magnet whereby lots of people came to the border who were not actually asylum-seekers. This magnet not only attracted illegal immigrants generally, but also produced an uptick in human trafficking across our border. (We now also have some limited evidence of jihadi recruiters spreading word about how to exploit the southwestern border.)