 He chaired the Democratic Lieutenant Governors Association and of the Southern Region of the National Lieutenant Governors Association.On March 1, 2010, Halter announced his candidacy in the 2010 U.S. Senate election, challenging two-term incumbent Blanche Lincoln in the Democratic primary.After one month of fund-raising, the Halter campaign announced that it had raised more than $2 million, mostly from out-of-state and from national labor unions.