Former President Donald Trump is already underwater by double digits with female voters in the polls. Now Trump will stand on stage next to a woman he has publicly and privately derided in language widely viewed as sexist. His allies hope he doesn’t make things worse when he squares off against Vice President Kamala Harris at the debate. In past debates against Hillary Clinton, Trump tried to undermine, belittle or humiliate both her and female debate moderators. This time, his advisers...