The field of candidates to take Ted Kennedy's senate seat continues its ebb and flow:
After lagging support from unions - one of his vital voter bases - U.S. Rep. Stephen Lynch (D-South Boston) said today he wouldn’t run for the late U.S. Sen. Edward M. Kennedy’s seat.
The exit of one of the heavyweight contenders - and the most conservative Democrat candidate - reshapes the race as two more Democrats consider jumping in.