The Megyn Kelly story is about best laid plans going awry—ironically awry. She bargained to be the biggest voice of the dominant news channel in America — and, as well, the best paid on-air personality in the history of television news. Instead, she’s become merely a contender among the knives-out egos in the contested (and ever dwindling) territory of network news—and at a steep discount to the brass-ring salary she might have had. The Murdochs, father and sons, thought Kelly was going to be their way of cleansing Fox of Roger Ailes and his brand of diss-the-elites conservatism—and of letting...