According to congressional newspaper the Hill, Michael Dukakis, 79, the former Massachusetts governor and 1988 presidential nominee, is the frontrunner to fill Kerry's seat until a special election can be held in the late spring or early summer.
Anticipating a heated Democratic primary for Kerry's seat, Gov. Deval Patrick (D) is expected to name an interim replacement who'd promise not to run in the special election.
Dukakis served as Massachusetts governor from 1975 to 1979, and then again from 1983 to 1991. He has remained politically active, campaigning for Elizabeth Warren, who won the state's other Senate seat in November, and teaching at Northeastern University in Boston.
The Hill also reported that the widow Sen. Ted Kennedy, Vicki Kennedy, is being considered as an interim replacement for Kerry.
Both Dukakis and Kennedy would be placeholders until the special election. Democratic Reps. Ed Markey, Mike Capuano and Stephen Lynch are all expected to contend for the vacated seat in that election. Republican Sen. Scott Brown, who lost to Warren in November, is also reportedly mulling over another senatorial run.