Representative Delahunt is talking about retiring -- and there's been some BMG discussion about Senator Therese Murray running, leader of the State Senate. Let's all hope she doesn't -- because that decision could be disastrous. She'd almost certainly win the primary if she ran (her very presence would scare away many competitors), but that's where her advantages run out.
Because of Murray's position as one of the two most powerful legislators (and figures) in this state, any Republican challenger could run against everything that's wrong with Beacon Hill. It wouldn't matter whether she should be held accountable for those problems or not, she could easily be scapegoated and blamed. After all, she's the boss.
Furthermore, this would undoubtedly be the first challenging race she's had in a very, very long time. It's difficult for powerful politicians who have held safe seats for a very long time to suddenly mount strong campaigns. Campaigning is ugly, tough work. Coakley's loss would almost certainly make Murray realize just how important it would be to really get out there and stay sharp, but there's a big difference between knowing you should do something and actually doing it. At the very least, Murray would need a strong primary challenge.
Democrats should plead with Delahunt to stay on. Not only is he a widely-respected politician with lots of seniority, but he's the best bet to hold the seat and would keep the Democrats from having to spread themselves that much thinner in this difficult election year. If he absolutely doesn't want to serve another term, primary voters should go for a sharp, active outsider candidate, who can't be pinned for Beacon Hill's problems, like Andrea Silbert.