Sen. John Thune is running against Democrat Brian Bengs to represent South Dakota in the US Senate.
Thune, who has more than $17 million in his coffers, will likely cruise to victory in the heavily conservative state.
Before being elected to the Senate, Thune served three terms representing South Dakota's at-large congressional district in the US House.
South Dakota is a ruby-red state; it only voted Democratic four times, most recently in 1964 when Lyndon B. Johnson handily defeated Barry Goldwater.
The money raceAccording to OpenSecrets, Thune has raised $12.5 million, spent $6 million, and has $17.2 million cash on hand, as of October 19.