[1] State Treasurer Tim Cahill left the Democratic Party in September 2009 ran as an independent candidate.

James McKenna received 27,711 certified write-in votes, which was a United States and Massachusetts electoral record.

Former Democratic National Committee National Chairman Steve Grossman won the Democratic primary against Boston City Councilor Stephen J. Murphy, and was opposed by Republican State Representative Karyn Polito (of Shrewsbury) in the general election.

In January 2010, Republican Scott Brown won a special election to fill the seat of Ted Kennedy.

All of Massachusetts's ten seats in the United States House of Representatives are up for election in 2010.

Massachusetts is expected to lose one congressional seat in the redistricting that will follow the 2010 census.