Democratic presidential candidates are vowing to boycott Thursday’s primary debate if a labor dispute between a food workers’ union and the company Sodexo is not resolved. The union, UNITE HERE Local 11, says Sodexo does not provide decent yearly wage increases, affordable healthcare or year-round work, and has vowed to stage a picket line during Thursday’s televised debate if an agreement is not reached. The union has been in negotiations with the food service company since March. All seven candidates slated to take the stage during Thursday’s debate have vowed not to cross the picket line.