The 1986 Wyoming gubernatorial election took place on November 4, 1986. Popular three-term Democratic Governor Edgar Herschler announced that he would not seek a fourth term, creating an open seat. Attorney Mike Sullivan emerged as the unlikely Democratic nominee, and faced former state representative Pete Simpson, the Republican nominee and the brother of then-U.S. senator Alan K. Simpson, in the general election. Despite Sullivan's political inexperience, he was able to defeat Simpson by a decisive margin, winning his first of two terms in office.
Democratic primary.
Results.
! scope="col" colspan="2" style="width: 15em" |Party
! scope="col" style="width: 17em" |Candidate
! scope="col" style="width: 5em" |Votes
! scope="col" style="width: 3.5em" |%
! colspan="3" style="text-align:right;" | Total votes
Republican primary.
Results.
! scope="col" colspan="2" style="width: 15em" |Party
! scope="col" style="width: 17em" |Candidate
! scope="col" style="width: 5em" |Votes
! scope="col" style="width: 3.5em" |%
! colspan="3" style="text-align:right;" | Total votes
Results.
Sullivan spent $102,219 during the primary and $150,000 in the general election compared to Simpson spending around $300,000 in the primary and $200,000 in the general election.
! scope="col" colspan="2" style="width: 130px"|Party
! scope="col" style="width: 17em"|Candidate
! scope="col" style="width: 5em"|Votes
! scope="col" style="width: 3.5em"|%
! scope="col" style="width: 3.5em"| ;templatestyles src="Template:Tooltip/styles.css" / ;±%
! colspan="3" style="text-align: right; margin-right: 0.5em" | Majority
! colspan="3" style="text-align: right; margin-right: 0.5em" scope=row | Turnout
References.
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