Editing Spoiler effect (section)

==== 2009 Burlington mayoral election ====
In [[2009 Burlington mayoral election|Burlington, Vermont's second IRV election]], spoiler [[Kurt Wright]] knocked out Democrat [[Andy Montroll]] in the second round, leading to the election of [[Bob Kiss]], despite the election results showing most voters preferred Montroll to Kiss.<ref name="Stensholt">{{Cite journal |last=Stensholt |first=Eivind |date=2015-10-07 |title=What Happened in Burlington? |url=https://ideas.repec.org//p/hhs/nhhfms/2015_026.html |journal=Discussion Papers |language=en |pages=13 |quote=There is a Condorcet ranking according to distance from the center, but Condorcet winner M, the most central candidate, was squeezed between the two others, got the smallest primary support, and was eliminated.}}</ref> The results of every possible one-on-one election can be completed as follows:
{| class="wikitable"
![[File:Democratic_Disc.svg|60x60px]]
!Andy Montroll ([[Democratic Party (United States)|D]])
|'''6262 (Montroll) –'''
591 (Simpson)
|'''4570 (Montroll) –'''
2997 (Smith)
|'''4597 (Montroll) –'''
3664 (Wright)
|'''4064 (Montroll) –'''
3476 (Kiss)
|[[Copeland score|'''4/4 Wins''']]
|-
! [[File:Progressive Disk.png|60x60px]]
!Bob Kiss ([[Vermont Progressive Party|P]])
|'''5514 (Kiss) –'''
844 (Simpson)
|'''3944 (Kiss) –'''
3576 (Smith)
|'''4313 (Kiss) –'''
4061 (Wright)
|[[Copeland score|'''3/4 Wins''']]
|'''''IRV winner'''''
|-
![[File:Republican_Disc.svg|60x60px]]
!Kurt Wright ([[Republican Party (United States)|R]])
|'''5270 (Wright) –'''
1310 (Simpson)
|'''3971 (Wright) –'''
3793 (Smith)
|[[Copeland score|'''2/4 Wins''']]
| colspan="2" |'''''Spoiler for Montroll'''''
|-
![[File:Independent Candidate Disc.svg|60x60px]]
!Dan Smith ([[Independent politician|I]])
|'''5570 (Smith) –'''
721 (Simpson)
|[[Copeland score|'''1/4 Wins''']]
| colspan="3" |
|-
![[File:Green_Disc.svg|60x60px]]
!James Simpson ([[Green Party of the United States|G]])
|[[Copeland score|'''0/4 Wins''']]
| colspan="4" |
|}
This leads to an overall preference ranking of:

# Montroll – defeats all candidates below, including Kiss (4,064 to 3,476)
# Kiss – defeats all candidates below, including Wright (4,313 to 4,061)
# Wright – defeats all candidates below, including Smith (3,971 to 3,793)
# Smith – defeats Simpson (5,570 to 721) and the write-in candidates

Montroll was therefore preferred over Kiss by 54% of voters, over Wright by 56%, and over Smith by 60%. Had Wright not run, Montroll would have won instead of Kiss.<ref name="Stensholt" /><ref>{{Cite web|url=https://www.electionscience.org/library/irv-and-core-support/|title=IRV and Core Support|website=The Center for Election Science|language=en-US|access-date=December 4, 2019}}</ref>

Because all ballots were fully released, it is possible to reconstruct the winners under other voting methods. While Wright would have won under [[Plurality voting|plurality]], Kiss won under [[Instant-runoff voting|IRV]], and would have won under a [[two-round system|two-round vote]] or a traditional [[nonpartisan blanket primary]]. Montroll, being the [[Condorcet winner criterion|majority-preferred candidate]], would have won if the ballots were counted using [[ranked pairs]] (or any other [[Condorcet method]]).<ref name=":gsmc">{{Cite journal |last1=Graham-Squire |first1=Adam T. |last2=McCune |first2=David |date=2023-06-12 |title=An Examination of Ranked-Choice Voting in the United States, 2004–2022 |journal=Representation |volume=61 |language=en |pages=1–19 |doi=10.1080/00344893.2023.2221689|arxiv=2301.12075 }}</ref>