Excerpt:
Cambridge City Councilor Nadeem A. Mazen, the state's highest-profile Muslim elected official, is planning a run against US Representative Michael E. Capuano in next year's primary, according to several people familiar with his thinking.
The councilor is plotting a bid to unseat the 10-term Democrat in a congressional district that includes Somerville, Chelsea, Everett, Randolph, half of Cambridge, one-third of Milton, and the majority of Boston.
If Mazen pulls the trigger, it would pit a 33-year-old MIT graduate, entrepreneur, and two-term city councilor against a 65-year-old former Somerville mayor and alderman — two progressives in one of the most Democratic districts in the country.