Nebraska Senator Ben Nelson has announced he will not seek another term in 2012, dealing a blow to Democrats who were hoping to keep control of the senate next year.

Politico:

"There's much more that needs to be done to keep America strong. And while I relish the opportunity to undertake the work that lies ahead, I also think it's time for me to step away from elected office, spend more time with my family, look for new ways to serve our state and nation. Therefore, I am announcing today that I will not seek reelection," Nelson said in a video posted on YouTube, titled "What's Next." "Simply put, it's time to move on."

Nelson apologized to his aides during a conference call that word of his retirement had leaked to POLITICO before he had a chance to personally inform them of his decision. Nelson began calling top Senate Democrats early Tuesday to tell them he was not running for reelection.

Nelson wavered in whether to retire, according to sources close to the Nebraska Democrat, telling aides that "some days it was yes, some days it was no."

He also said on the call that the "tea party must be stopped."

Sen. Claire McCaskill (D-Mo.), who also faces a tough reelection battle next year, sent a note to Nelson saying how sad she was over his decision to step down next year. McCaskill jokingly added to her note: "Nebraska still sucks."

Nelson was at the top of the GOP hit list as far as targets in 2012. His more moderate image didn't sit well with the Democratic base and Nebraska has historically been a GOP stronghold. Unless the Democrats can coax Bob Kerrey out of retirement and get him to run for Nelson's seat, the Republicans should have a fairly easy pick up next November.