‘Fifteen years ago if somebody was up here and said that, they’d say ‘What’s wrong with him?’ ” President Trump said Tuesday in his State of the Union address. Said what? “Surely we can all agree no state can be allowed to rip children from their parents’ arms and transition them to a new gender against the parents’ will.” When Democratic lawmakers declined to stand in assent to that statement, the president declared: “These people are crazy.” Mr. Trump had introduced Sage Blair, 19, and her adopted mother (and biological paternal grandmother), Michele. Their story is unbelievable—and part of a...