Democrats in the Senate might lose another seat. Sen. Ben Nelson of Nebraska is will not run for reelection, a top Democratic source told NBC. "He will be the least missed member of the Democratic caucus next year," the source said, referring to Nelson's conservative politics and tendency to vote with the Republicans. At home, the 70-year-old faced criticism over his support for Obama's economic stimulus packages and healthcare plan and was the target of negative ads funded by GOP-affiliated outside groups; he faced a tough reelection fight, according to The New York Times. Politico reports that the White House and top Senate Democrats, fearful that they'd lose the Senate, pressured Nelson to stay. Republicans only need four seats to take control of the chamber, and 23 Democratic-controlled seats will now be up for grabs. Former Nebraska Sen. Bob Kerrey, also a Democrat, is reportedly considering a run for Nelson's seat.