North Dakota congressional district
Since the reapportioning of Congressional seats following the 1970 census, all of North Dakota is contained within one Congressional District. At the 1972 election, this meant that the two North Dakota congressional districts were merged into one, and Mark Andrews (Republican incumbent in the 1st Congressional District) won the newly-merged district with 72.7% of the vote. Arthur Link, Democrat incumbent in the 2nd Congressional District, did not stand for re-election, but was successful in winning election as the State's Governor.
In the post-Watergate 1974 elections, Andrews was challenged by Byron Dorgan (D) and was re-elected with 55.7% of the vote. In 1976 and 1978 he increased his majority over Democrat challengers Lloyd Omdahl and Bruce Hagen respectively.
Andrews ran (successfully) for the United States Senate in 1980 and so stood down. In his place, Byron Dorgan ran for the open seat and defeated Republican Jim Smykowski by 56.8% to 42.6%. He obtained re-election with his percentage vote never dropping below 70% until 1990 (when Republican Edward T. Schafer, later to be elected Governor of the State, held him to only 65.2%). Dorgan in turn ran for a Senate seat in 1992 and left an open seat which was assessed as leaning Democratic. Republican John Korsmo lost to Democrat Earl Pomeroy by 39.4% to 56.8%.