Missouri labor unions were successful in getting enough signatures to all but guarantee the state’s new right-to-work law won’t go into effect a week from now as Gov. Eric Greitens had planned. But the real battle is just getting started. Come November 2018, voters around the state will determine whether to kill or keep the law, which bars unions and employers from requiring all workers in a bargaining unit to pay dues. But only 10 percent of Missouri workers are in a union.