The Fox News moderators went after Trump harder than any of his opponents during last night’s debate. He started the debate on the defensive over his refusal to rule out an independent bid. Megyn Kelly, one of three moderators, then memorably pushed him on his history of misogynistic comments: “You’ve called women you don’t like ‘fat pigs, dogs, slobs, and disgusting animals.’” Later, she wondered when he decided to become a Republican and asked about his flip-flops on abortion. The other moderators, Chris Wallace and Breit Baier, forced Trump to defend his past support for a single-payer health-care system, his...