US Representative Michael Capuano

Warchest: $921,550

Chance of running: Almost certain. ''If the Senate seat becomes vacant, Congressman Capuano would strongly consider seeking the open seat,'' said spokeswoman Alison Mills.

Pro: Political parlor gamers suggested the Kennedys would get behind a Capuano bid, because if he won the family could reclaim a legendary Congressional seat once held by John F. Kennedy and Joseph P. Kennedy II. Possible successors would be one of Joseph Kennedy’s young sons.

Con: He has a strong role in Congress and is among those in the inner circle of House Speaker Nancy Pelosi.