Rochelle Nguyen's mailbox has been inundated with glossy campaign mailers. Because her household includes registered Republicans as well as Democrats, the materials run the gamut of hot-button topics under discussion in the midterms. But one thing is different this election, the Nevada assemblywoman said: “I can tell you, everything from social media messaging to mailers – I've never received so much in Vietnamese.” The pile of political mail sitting in Nguyen's home in Las Vegas is one indicator that Asian American communities have emerged as a critical constituency for both Republicans and Democrats, particularly in key battlegrounds like Nevada's 3rd...