Facing a tough re-election next year, Nebraska Senator Ben Nelson has announced that he will retire at the end of his current term. NBC's Mark Murray dicsusses how this could affect the balance of power in the Senate.
The conservative Nelson, who often voted with Republicans "will be the least missed member of the Democratic caucus next year," said that same high-ranking Democratic source.
While Nelson may have often voted with Republicans, his decision not to run comes as a blow to Democrats' hopes of maintaining control of the Senate, unless Democrats find a top-notch recruit like former Nebraska Sen. Bob Kerrey (D), who is reportedly considering a run with Nelson's seat open.
**UPDATE** from AP (3:27 p.m. EST): Democratic Sen. Ben Nelson tells supporters he'll retire: "Simply put: It is time to move on"