Kansas Republican Sam Brownback announced Thursday that he will not seek a third, six-year term in the U.S. Senate.
Brownback made his announcement at the Statehouse in Topeka, saying he owed it to Kansans to keep his word and retire more than keeping seniority in the Senate.
"This is something that I need to do," he said. "I would lose a lot more and the people of Kansas would lose a lot more if I broke my word."
Brownback was elected to the Senate in 1996 to fill the unexpired term of Sen. Bob Dole who resigned to be the GOP nominee for president. Brownback then won full, six-year terms in 1998 and 2004.
"I love doing this," he said. "Your word is your bond. Once you give it, you stand by it."
It is widely expected that Brownback, 52, will return to Kansas and run for governor in 2010. However, Brownback declined to say what he would be doing after his term ended.