Rep. Niki Tsongas (D) broke ranks with the men in her House delegation, endorsing state Attorney General Martha Coakley (D) in the special Senate election Wednesday. Tsongas, who herself went to Congress via a special election, touted Coakley’s record as attorney general and service to the state. In backing the attorney general, Tsongas passed over her House colleague, six-term Rep. Mike Capuano, who is one of three men running against Coakley in the Dec. 8 Democratic primary. Four other Massachusetts Democratic House Members have endorsed Capuano: Reps. Jim McGovern, Barney Frank, John Tierney and Stephen Lynch.

Coakley continues to lead the field, according to a Western New England College Polling Institute survey released Monday, with Capuano and businessman Stephen Pagliuca essentially tied for second, and Alan Khazei, founder of a national community service group, coming in fourth. The four Democrats got together for their first debate in Boston on Monday, a low-key forum that did little to shake up the race.

The winner of the Democratic primary is expected to win comfortably over likely Republican nominee state Sen. Scott Brown, in January.