The 1990 United States Senate election in Iowa was held on November 5, 1990. Incumbent Democratic U.S. Senator Tom Harkin sought re-election to a second term in office. Harkin was opposed by Republican U.S. Congressman Tom Tauke, from Iowa's 2nd congressional district, and both Harkin and Tauke won their primaries uncontested. Though Harkin performed slightly worse than he had six years earlier, he was successful in his re-election bid and defeated Tauke. Democratic primary Candidates Tom Harkin, incumbent United States Senator Results Republican primary Candidates Tom Tauke, U.S. Representative Results General election Results See also 1990 United States Senate elections References Iowa 1990 1990 Iowa elections