How low-wage service workers are changing the face of labor….Last year, Crawford joined the “Fight for 15” campaign, a labor and community-supported project that aims to improve conditions for workers in Chicago’s central business districts. The campaign demands a $15 minimum wage and the right to form unions without interference from management…. These strikes have been the defining tactic of a new movement of low-wage service workers that has gained momentum in 2013. Small groups of workers have launched sudden strikes against big chains such as Wal-Mart and McDonald’s, as well as small employers such as car washes, laundries and taxi companies. In many cases, only a minority of employees were involved, sometimes from multiple workplaces. The strikes have typically been sudden and short, lasting just long enough to broadcast their message. A few campaigns have won union recognition; more have won small victories like a pay raise or a scheduling change. But taken together, the campaigns have surprised experts like Kate Bronfenbrenner, director of labor education research at Cornell University, who says she could not have imagined such an upsurge even two years ago….