Does it violate human rights to hold children in fenced enclosures in grim facilities that are bone-chillingly cold for weeks on end? Is separating children from their parents a form of cruel and unusual punishment? When does a crisis justify the kind of treatment normally seen as inhumane?
The furious debate over migrant detention along the nation's southwest border with Mexico has put these questions front and center in American politics. But they're not new. The treatment of people on the margins of American life - criminals, immigrants, civilians in overseas war zones - has always proven a challenge to our democratic ideals.