(WASHINGTON) -- The senior senator from Nebraska has decided not to run for re-election next year. Retiring at the end of his second term, Nebraska's Ben Nelson becomes the seventh Senate Democrat to announce his retirement this session.
In 2012, Democrats will find themselves defending 23 senate seats - far more than Republicans, who have 10 members up for re-election next year. If four seats change hands into the GOP column, so too would control of the Senate.
In a statement Tuesday, President Obama thanked Nelson for "his years of service representing the people of Nebraska, first as Governor and then for more than a decade in the United States Senate."
"Over the course of his career, Ben’s commitment to working with both Democrats and Republicans across a broad range of issues is a trait far too often overlooked in today’s politics. Michelle and I commend Ben for his service, and wish him and his family well in the future," the president said.
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