When President Donald Trump promoted Stephen Miller to White House chief of staff, Democrats started fuming almost instantly. That reaction alone tells you it was a good move. I suspect Democrats thought the fallout from the midterms would scare Trump into submission. They wanted a chastened president who would spend his final two years tiptoeing around them. Instead, Trump handed the most powerful staff job in Washington to a man they deeply despise, and they read the move as defiance. They read it correctly. "Donald Trump learned nothing from his historic defeat. Stephen Miller is the architect of the most...