The revelers watched in stunned disbelief, cocktails in hand, dressed for a night to remember. On the big-screen TV a headline screamed in crimson red: “Projected Winner: Scott Walker.” It was 8:49 p.m. In parts of Milwaukee, people learned that news networks had declared Wisconsin’s governor the winner while still in line to cast their votes. At the election night party for Walker’s opponent, Milwaukee Mayor Tom Barrett, supporters talked and cried and ordered more drinks. Barrett soon took the stage to concede, then waded into the crowd where a distraught woman slapped him in the face.