Dennis Ray "Denny" Rehberg (born October 5, 1955) is an American politician and member of the Republican Party. He served as the Lieutenant Governor of Montana from 1991 to 1997 and as the U.S. Representative for Montana's at-large congressional district from 2001 to 2013. Rehberg was the Republican nominee for the United States Senate in 1996 and 2012, losing to Max Baucus 50% to 45% and to Jon Tester 49% to 45%, respectively. He subsequently became a co-chairman at Mercury, a Washington D.C.