The 1990 Wyoming gubernatorial election took place on November 6, 1990. Incumbent Democratic Governor Mike Sullivan ran for re-election. In the general election, he faced Republican nominee Mary Mead, a businesswoman and the daughter of former U.S. Senator and Governor Clifford Hansen. Owing to Sullivan's personal popularity, he won re-election over Mead in a landslide, marking the fifth straight Democratic victory in Wyoming's gubernatorial races, a streak that has yet to be broken by either party.
The central committee of the Wyoming Republican Party interviewed Hugh Duncan, Jack Sidi, Charles Scott, and Carroll Miller and scored them as possible gubernatorial nominees. Duncan received a rating of 83%, Sidi received 79%, Scott received 66%, and Miller received 23%.[6] Duncan withdrew from the election on March 2, 1990, stating that he was unable to convince people of the differences between him and Sullivan.[8]
Tom Thorson, a Republican committeeman from Natrona County, announced Mary Mead's candidacy at the Natrona County Republican Convention on March 6, as Mead was unable to attend due to snow.[14] Mead formally announced her campaign on March 9, after Duncan and Mike Lindsey both dropped out and announced their support of her.[15]Stanley K. Hathaway, a former governor, served as her campaign manager.[16]Cynthia Lummis later served as her campaign manager.[17]Nyla Murphy, a member of the state house who lost her committee leadership positions due to policy disagreement with Republican leaders, announced that she would run for one of five statewide offices in Wyoming.[18] She launched her gubernatorial campaign on June 8, with Charles Huff and Linda Burkhart as her campaign managers.[19] Mead spent over $280,000 during the primary, twenty times greater than Murphy's expenditure of $7,200.[20]
Sullivan recorded a message for a test of Wyoming's Emergency Broadcast System, but it was replaced as some radio stations would not air it due to the equal-time rule.[22] The National Organization for Women declined to endorse either of the candidates and instead supported a write-in candidacy for Murphy.[23] Mead and Sullivan participated in a debate hosted by KTWO-TV on October 23, 1990, and KTWO-TV stated that Mead violated the rules by using notes.[24]
Mark Hughes, the chair of the Wyoming Republican Party, criticized Mead as being unprepared after she lost the election, but also criticized the media for giving Sullivan front-page coverage while "Mead was on the B-section".[25] Hughes later apologized for criticizing Mead.[26] He did not seek reelection as chair, but stated that he made that decision months before his criticism of Mead.[27]
Mead received $158,798 and Sullivan received $154,562 from individual contributions. Mead paid $183,104 to consultant Sandler-Innocenzi and $12,441 to Tony Payton, accounting for around half of her expenditure.[28] Sullivan received almost $57,900 from political action committees compared to $21,600 for Mead. The Republican Party of Wyoming contributed $43,200 to Mead while the Democratic Party of Wyoming contributed $8,763 to Sullivan. Mead received $157,000 in loans from her father and brother while Sullivan borrowed nothing. During the campaign Sullivan raised $225,681 and spent $196,733 for an ending surplus of $28,948. Mead raised $395,532 and spent $416,313 for an ending deficit of $20.[29][30]