Milwaukee, Wis. — As the polls closed, from 6 p.m. to 8 p.m. Central, I was an observer at an elementary school in Ward 177, a blue-collar area, just a few steps from Democrat Tom Barrett’s campaign office on Martin Luther King Jr. Boulevard. The lines were strong for the first hour, but during the last hour, things began to fizzle. Outside, there were a couple of college-age men making $25 an hour to canvass, but even that pair — two fraternity types — were unethusiastic. “I’m not going to Barrett’s party,” one told me. He was going to spend...