 Unable to seek a third term as State Treasurer in 1980, he was an unsuccessful candidate for Governor of Missouri, losing the Democratic Party nomination to incumbent Joseph P. Teasdale.Spainhower threw his hat into the ring for the special 1976 Democratic primary for U.S. Senate after the initial winner Jerry Litton was killed while flying to the victory party.Spainhower lost to Warren Hearnes who garnered 63.3% of the vote.