IRS launches audit of teachers union Associated Press WASHINGTON -- The IRS is auditing the nation's largest teachers union, scrutinizing an organization that works energetically to elect candidates but files tax returns reporting zero political expenditures from member dues.The National Education Association promised Monday to cooperate, but its president, Reg Weaver, said the union "will not be silenced" by the audit or the conservative law firm that requested it.NEA spokeswoman Kathleen Lyons said the audit began last week. "It will be a complete, thorough audit," she said. "The IRS has not singled out any particular aspect of our activities."Weaver and...