U.S. Sen. Catherine Cortez Masto’s win in Nevada guaranteed that Democrats would retain control of the Senate after the 2022 midterm elections. It also confirmed the strength of the Democratic Party in the West. Since 1992, Democrats have flipped the region away from Republican control, a shift that began with the end of the Cold War and carried through a Pacific Coast economic recession, anti-racism demonstrations and violence in Los Angeles and the area’s increasing diversity. I am a professor of political science who has published on the subject of critical elections and how regional realignments in voting patterns have...