In the annals of American labor relations, history sometimes reverses course. That certainly was true yesterday in Missouri. By a 2-to-1 margin, voters overturned a law passed and signed early last year to protect private-sector workers under union contract from being forced to pay dues in order to keep their jobs. The referendum, known as Proposition A, had been placed on the ballot via petition. Union leaders now are serving notice that the Missouri vote is the beginning of nationwide campaign to repeal similar “Right to Work” laws in 27 other states. “The defeat of this poisonous anti-worker legislation is a victory for all workers across the country,” crowed AFL-CIO President Richard Trumka. His declaration seems a case of myopia.