Rep. John Tierney (D-MA) has been in Congress for 17 years and is in a deeply Democratic district, but that has not helped him avoid two heated contests for his reeection. He faces four Democratic challengers in a primary Tuesday, with one, Seth Moulton, winning the endorsement of both major Boston papers. If he wins, Tierny would then go on to oppose Republican candidate Richard Tisei, who he beat by 1% in 2012. Kylie Atwood reports.
