Input: Relationship: 'be president of', Argument/Subject 1: 'john engler', Argument/Subject 2: 'national association of manufacturer'

Answer: John Engler , president of the National Association of Manufacturers , said that if Wal-Mart 's United States work force of 1.4 million were unionized , that could mean $ 500 million in additional union dues collected each year -- tens of millions of which might be used to support Democratic causes and candidates .