 South Dakota politics are generally dominated by the Republican Party, and the state has not supported a Democratic presidential candidate since 1964 — even George McGovern, the Democratic nominee in 1972 and himself a South Dakotan, did not carry the state.Additionally, a Democrat has not won the governorship since 1978.As of 2006, Republicans held a ten percent voter registration advantage over Democrats and hold majorities in both the state House of Representatives and Senate.