[citation needed] Barnett won the general election by defeating Michael Butler.
[1] Barnett was re-elected by defeating Democrat Randy Turner and Libertarian Bert Olson.
[citation needed] As of October, 2019, Barnett is the longest-serving attorney general in South Dakota history, with 12 years of service.
Barnett argued on behalf of the state, winning a 7–2 decision that the federal Flood Control and Cheyenne River Acts had abrogated the tribe's right, guaranteed under the Fort Laramie Treaty, to regulate hunting and fishing on their lands by non-Indians.
[citation needed] Barnett argued that an 1894 federal statute, ratifying an agreement pursuant to the Dawes Act, had diminished the boundaries of the Yankton Sioux Reservation, as they had been established in an 1858 treaty.