I have focused on Ben Nelson, and the Cornhusker Kickback, repeatedly.  The big question was whether Nelson would run for reelection, with the Democrats hoping he would as the best chance of keeping the seat.

It turns out he is retiring, via Politico:

Democratic Sen. Ben Nelson of Nebraska will announce today that he is  retiring after two terms, a serious blow to Democratic efforts to hold onto  their majority in the chamber next November.

Nelson is scheduled to hold a press conference back home in Nebraska as early  as today to make his decision official, said several Democratic insiders close  to the leadership.

Updates to follow:

Former Senator Bob Kerrey has not ruled out a run on the Democratic side if Nelson retired, but he has had a rocky road since leaving office, including a run as President of the ultra-liberal New School in New York City.  His tenure there may not hurt him as much as expected, as he ultimately left after butting heads with the even more liberal faculty and student body, as I reported back in April 2009.

Here’s the Farewell to Ben video created by a Legal Insurrection reader and physician in Nebraska which I ran on December 8: