Commentary by Jacqueline Bennett newsandviewsjb.com   As America’s middle class continues to shrink, union workers are struggling to save it.   “Whether one is concerned about middle-class wages, incomes, mobility in relationship to the rich and the poor, one policy solution can help strengthen the middle class: strengthen unions.” David Madland and Alex Rowell wrote in a piece titled ‘Unions Help the Middle Class, No Matter the Measure.’   Unions, they said, increase workers’ wages and benefits, boost economic mobility for future generations, reduce runaway increases at the top, raise the share of national income going to the middle class, reduce inequality, decrease poverty and improve worker’s well-being. Nonetheless in the past few decades union membership has dwindled. The decline, they add, has been…