Ask voters in North Carolina’s Research Triangle what November’s midterm elections are about and one will tell you drones. A second will say closing the prison at Guantanamo Bay, Cuba. Yet another, the middle-class squeeze. At a Sunday school classroom in Ypsilanti, Mich., voters are concerned about deteriorating roads, teen sex parties, truancy in schools and violent crime. Six hundred miles west at a Republican campaign office in Urbandale, Iowa, people fear that America is on an irreversible decline — like Germany after World War I, as one man predicted. Across Colorado, voters are thinking about a whole other set...