This looks like an intriguing indicator of an old-style Democrat frustrated with the stances of his party today, but it also might complicate the chances for a GOP pickup in Massachusetts:

James Sheets, the former six-term mayor of Quincy, said this afternoon he is considering running for Congress as an independent.
Sheets, 74, said he will decide in the “next few days” whether to run for the 10th Congressional District seat held by U.S. Rep. William Delahunt, D-Quincy, who announced in March he would not seek reelection…
Norfolk District Attorney William Keating and state Sen. Robert O’Leary are competing for the Democratic nomination. And Republicans Joseph Malone of Scituate, a former state treasurer, and state Rep. Jeffrey Perry of Sandwich are opponents in their party’s primary . . .
Sheets, who now teaches a course on government part-time at Quincy College, said he has been considering running “since they passed the Obama health care bill.”
Calling the bill “inhumane and cruel,” Sheets criticized Congress for agreeing to slash “half a trillion dollars” from Medicare over the next decade.
“What about the seniors who have done so much for this county in their lifetimes?” Sheets said. “People in their golden years were supposed to be able to rely on Medicare.”
A Democrat all his life, Sheets said he has grown disenchanted as the party has shifted further to the left.
“My problem now, I feel that the leadership of the Democratic party has really forsaken the average working man,” he said.

This is a district scored D+5 in the Cook Partisan Voting Index, making it technically the most Republican in the state.