CNN — Confronted with a barrage of negative social media posts from former President Donald Trump aimed at his wife, second gentleman Doug Emhoff eschewed machismo or defensiveness. “That’s all he got?” he said Tuesday of the attacks on Vice President Kamala Harris, the new and historic presumptive Democratic presidential nominee. His response in that off-the-cuff moment offered insight into the Harris-Emhoff dynamic: The second gentleman is uniquely positioned to confidently serve in a supporting role to a woman vying to the most powerful person in the country. Emhoff has spent the last four years getting comfortable with being the...