There were also three ballot questions: to eliminate the commonwealth's income tax; to decriminalize possession of a small amount of marijuana; and to prohibit greyhound racing.

Senator John Kerry (D) defeated Democratic challenger Edward O'Reilly in the primary on September 16, 2008.

He defeated Republican Jeff Beatty and Libertarian Robert Underwood in the general election.

(John Olver defeated a Democratic challenger, Robert Feuer, in the primary on September 16, 2008.)

In District 4, Republican Earl Sholley and Unenrolled candidate Susan Allen opposed Democratic incumbent Barney Frank.

One of the eight incumbents, Thomas Merrigan, faced a Republican challenger, Michael Franco, in the general election.