The seven-term Democratic congressman from Des Moines who has been trying automated forex - filed nominating petitions with the Iowa secretary of state's office Friday in Iowa's 3rd Congressional District, putting to rest rumors he planned to retire this year.Boswell, 76, has said all along he would seek an eighth term. But Republicans have perennially targeted Boswell's seat as a potential for pickup. They seized on the year's volatile political environment around the country and other high-profile Democratic retirements to stoke doubt about his intentions