Rep. Michael Capuano, D-Mass., made it official Friday. He's not running against Sen. Scott Brown, R-Mass.
Capuano, who had shown intermittent interest in the race after a disappointing performance in the 2009 primary for the seat, said he looked forward to seeking reelection to his House seat in 2012.
"After serious personal reflection, I have decided not to seek the United States Senate seat for Massachusetts at this time," Capuano said in a statement. "There are several good candidates currently in the race and I am fully satisfied that any nominee from this group will represent Massachusetts effectively in the Senate."
The party remains without a top contender to challenge Brown, who remains popular and reported a nearly $10 million war chest at the end of June. But former Consumer Financial Protection Bureau staffer Elizabeth Warren has begun preparing a campaign and is the favorite of Democratic officials in Washington.
Warren keynotes a big-ticket labor union breakfast on Monday. That event, perennially packed with longtime Capuano allies, will serve as Warren's first foray into public campaigning, after weeks of closed-door activist meetings.