Brownback made that announcement at the Statehouse, saying he owed it to Kansans to keep his word and retire more than keeping seniority in the Senate.
It's widely expected that Brownback will return to Kansas and run for governor in 2010. However, the 52-year-old Brownback declined to say Thursday what he would be doing after his term ended.
(Copyright 2008 by The Associated Press. All Rights Reserved.)