Michelle Obama assailed President Donald Trump on Monday for ripping migrant children from their parents and throwing them into cages, picking up on a frequent and distorted point made widely by Democrats. She's right that Trump's now-suspended policy at the U.S.-Mexico border separated thousands of children from their families in ways that had not been done before. But what she did not say is that the very same 'cages' were built and used in her husband's administration, for the same purpose of holding migrant kids temporarily. In her remarks Monday night during her keynote address at the Democratic National Convention,...