Robert Warren Bob Schaffer (born July 24 1962) was a Republican member of the United States House of Representatives from the State of Colorado in the 105th Congress and the two succeeding Congresses (January 3 1997 to January 3 2003). In 2004 Schaffer lost in the primary election to be the Republican nominee for a U.S. Senate seat. He was the Republican nominee for Colorado's other Senate seat in the 2008 election which he lost to Democratic nominee Mark Udall. Given a list of categories: company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work, what category does the paragraph belong to?
The answer to this question is:
Office Holder