Congresswoman Jasmine Crockett was in Dallas when the shocking news broke. At a shopping mall in the suburb of Allen, a gunman shot and killed eight people, including three children. He was later revealed to have posted photos online displaying Nazi tattoos on his arm and torso. “I was texting my mom to see where she was, because it’s a suburb 30 miles north of my district, and on the weekends she usually goes shopping,” Crockett, 42, recalls in an interview at her office in Washington. “She texted me: ‘I’m at my friend’s house. Why?’ ‘Because of Allen.’ ‘What’s going...