In 1931, 1939 and 1941 Aandahl was member of the
North Dakota State Senate. From 1945 to 1951 he was governor of the state, and during his tenure, natural resources were protected and conservation programs were promoted. He was elected as a
Republican to the
Eighty-second United States Congress (January 3, 1951 – January 3, 1953). He was not a candidate for the
Eighty-third Congress in 1952, but was an unsuccessful candidate for the
United States Senate, losing 58%-42% to incumbent
William Langer in the Republican Primary. Aandahl then ran in the general election against Langer and Democrat
Harold A. Morrison and finished in third place and 10% of the vote. From 1953 to 1961 he was appointed
Assistant Secretary of the Interior during both of President Dwight D. Eisenhower's administrations. ==Death==