Analysis: Closely Contested Congressional Races In Mass.

Thursday night, the candidates in one of Massachusetts' most closely contested congressional races faced off in a fiery fourth debate.

Democratic incumbent U.S. Rep. John Tierney sparred with his Republican challenger Richard Tisei for the 6th Congressional District.

Democratic analyst Dan Payne and Republican analyst Todd Domke joined WBUR’s Morning Edition for some analysis of that race and others across the state's congressional map, including the 4th and 9th districts.