Editing By-election (section)

=== Upsets ===

==== Australia ====

The [[1918 Swan by-election]] was held following the death of [[John Forrest]]. The seat was traditionally a safe seat for the [[Nationalist Party (Australia)|Nationalist Party]] against the [[Australian Labor Party|Labor Party]], but the emergence of the [[National Party of Australia|Country Party]] lead to a "[[Spoiler effect|three-cornered contest]]". As Australia used a [[first-past-the-post]] system at the time, the conservative vote was split between the Country and Nationalists, allowing Labor candidate [[Edwin Corboy]] to come in first place and win the seat. The Swan by-election is cited as the reason for the introduction of [[Instant-runoff voting|preferential voting]], to prevent Labor from benefiting from a divided opposition in the future.<ref>{{Cite web |last=Green |first=Antony |author-link=Antony Green |year=2004 |title=History of Preferential Voting in Australia |url=http://www.abc.net.au/elections/federal/2004/guide/prefhistory.htm |access-date=2020-06-15 |website=Antony Green Election Guide: Federal Election 2004 |publisher=Australian Broadcasting Corporation}}</ref>

The [[2018 Wentworth by-election]] was held after the resignation of former prime minister [[Malcolm Turnbull]], who had served as the member for [[Division of Wentworth|Wentworth]] since 2004. Wentworth was considered an exceptionally safe seat for the [[Liberal Party of Australia|Liberal Party]], as it had only ever been held by the Liberal Party and its predecessor parties since its creation in 1901. Former Ambassador to Israel [[Dave Sharma]] was preselected as the Liberal Party's candidate for the by-election. The major challenger in the by-election was independent candidate [[Kerryn Phelps]]. A huge 17.7% [[two-party-preferred]] swing was required for the Liberal Party to lose the seat. Ultimately, the Liberals suffered a 19.0% swing to Phelps, the largest by-election swing in Australian history, which won her the seat. This loss deprived the Liberal Party of its majority in federal Parliament, forcing them into a [[minority government]].

==== Canada ====
In 1942, the Conservatives' [[Arthur Meighen]] (who had already served as Prime Minister during the 1920s) sought to re-enter the [[House of Commons of Canada]] through a by-election in [[York South]]. His surprise defeat at the hand of [[Joseph W. Noseworthy]] of the [[Co-operative Commonwealth Federation]] ended his political career, and may also have been a factor in the Conservative Party's decision to move to the left and rebrand itself the Progressive Conservative Party under Meighen's replacement. Noseworthy's victory was also a significant breakthrough for the CCF giving it credibility as a national party where it has previously been seen as a Western Canadian regional protest party.

On November 1, 1944, General [[Andrew McNaughton]] was appointed to Cabinet as [[Minister of National Defence (Canada)|Minister of Defence]] without having a seat in parliament, after his predecessor resigned during the [[Conscription Crisis of 1944]]. A by-election was arranged in [[Grey North]] which the opposition [[Progressive Conservative Party of Canada|Progressive Conservative party]] contested. The major campaign issue became the government's policy of "limited conscription" during World War II, which McNaughton supported, and which the Conservatives rejected. They called, instead, for "full conscription". McNaughton was defeated in the February 1945 by-election. As a result, with confidence in his government undermined, Prime Minister [[William Lyon Mackenzie King]] called the [[1945 Canadian federal election|1945 federal election]] several weeks later; originally he had intended to postpone the election until the war was clearly won. McNaughton sought a seat in the 1945 contest but was again defeated, and resigned shortly after.

The most recent example of a cabinet minister appointed from outside parliament having to resign after losing a by-election was in 1975, when Minister of Communications [[Pierre Juneau]] was appointed to [[Pierre Trudeau]]'s Liberal cabinet directly from the private sector, and tried to enter parliament through a by-election in [[Hochelaga (electoral district)|Hochelaga]]. Juneau unexpectedly lost to the Progressive Conservative candidate and resigned from cabinet 10 days after his by-election defeat.

In [[Ontario]], [[John Tory]], leader of the [[Progressive Conservative Party of Ontario]] ran in a 2009 by-election in [[Haliburton—Kawartha Lakes—Brock (provincial electoral district)|Haliburton—Kawartha Lakes—Brock]], after he convinced one of his caucus members to step down, in hopes of re-entering the [[Ontario legislature]]. His by-election defeat resulted in his resignation as party leader.

==== Hong Kong ====

In the [[March 2018 Hong Kong by-elections]], the [[pro-democracy camp]] lost their majority status for the first time in the [[Geographical constituency]] part of the [[Legislative Council of Hong Kong]] By-elections were held after six pro-democracy lawmakers were disqualified by the [[High Court of Hong Kong]] during the [[oath-taking controversy]]. The pro-democracy camp was considered safe in the de facto [[first past the post]] by-election because both pro-democracy camp and [[pro-Beijing camp]] would only nominate one candidate to fill in the by-election. However, the pro-democracy camp lost twice in [[Kowloon West (1998 constituency)|Kowloon West]], which had been considered a safe seat for them.

==== Singapore ====
{{main|By-elections in Singapore}}

Under Article 49(1) of the [[Constitution of Singapore]],<ref>{{cite web | url=https://sso.agc.gov.sg/Act/CONS1963?ProvIds=pr49-#pr49- | title=Constitution of the Republic of Singapore – Singapore Statutes Online }}</ref> a by-election should be called for any vacancy arising from a constituency—particularly [[Single Member Constituency]]<ref>{{cite web | url=https://sso.agc.gov.sg/Act/PEA1954?ProvIds=pr24-#pr24- | title=Parliamentary Elections Act 1954 – Singapore Statutes Online }}</ref>—within a reasonable time period.<ref>{{cite web | url=https://www.elitigation.sg/gd/s/2013_SGCA_39 | title=&#91;2013&#93; Sgca 39 }}</ref> Since the introduction of partial self-governance in 1955, 34 by-elections have been held, and some have been major upsets:
* In the [[1957 Cairnhill by-election]], the then-ruling [[Labour Front]] government saw its vote collapse to 19.23% from 47.58% in the [[1955 Singaporean general election|previous general election]].
* Each by-election in 1961 was important for the survival of the ruling party's small majority.
** After being dismissed as the [[Ministry of National Development (Singapore)|Minister for National Development]], [[Ong Eng Guan]] resigned his seat. Standing in the [[1961 Singaporean by-elections|1961 by-election in Hong Lim]] as an independent, he polled 73.31% of the vote, the largest loss of votes for an incumbent party in a by-election.
** The [[1961 Singaporean by-elections|1961 by-election in Anson]] saw a comeback by the opposition leader, the [[Workers' Party (Singapore)|Workers' Party]] Chairperson and former [[Chief Minister of Singapore|Chief Minister]], [[David Marshall (Singaporean politician)|David Marshall]].
* In the [[1981 Anson by-election]], the Workers' Party Secretary-General [[J. B. Jeyaretnam]] broke the ruling PAP's monopoly in Parliament, marking the first opposition presence since 1966 and the re-entry of the Workers' Party into Singapore's legislature since 1961.
* The [[2013 Punggol East by-election]] was the first time the [[People's Action Party]] lost a seat in a by-election since 1981 and the last time the ruling party failed to retain a constituency in a by-election.

==== Ireland ====

A [[2014 Dublin South-West by-election|by-election]] held in [[Dublin South-West]] during 2014 provided a very surprising upset. The [[Sinn Féin]] candidate, Cathal King, was the favourite to take the seat. Sinn Féin had done extremely well in the area during [[2014 Irish local elections|that year's local elections]]. Sinn Féin captured high percentages of the first preference vote across the constituency. However, the [[Anti-Austerity Alliance]] candidate, [[Paul Murphy (Irish politician)|Paul Murphy]], was elected on the eighth count. Although Murphy had received a lower first preference total than Cathal King, he outperformed the Sinn Féin candidate in attracting transfers. Murphy then took his seat in the [[31st Dáil]]. As a direct result of this defeat in the by-election, Sinn Féin hardened their stance against [[Irish Water]] and called for the complete abolition of water charges in Ireland.

==== United Kingdom ====
In 1965, the [[British Foreign Secretary]] [[Patrick Gordon Walker]] stood in the [[1965 Leyton by-election|Leyton by-election]] for election to the [[UK Parliament]], having been defeated in controversial circumstances in [[Smethwick in the 1964 general election|Smethwick]] at the previous year's [[1964 United Kingdom general election|general election]]. His appointment as a senior minister while not a member of either house of Parliament was against convention, and he therefore sought to regularise the position by standing in the first available by-election, which was at [[Leyton]] in January 1965. However a strong swing against Labour resulted in Gordon Walker's defeat: as a result, he resigned as Foreign Secretary.

==== United States ====

In 2010, [[Republican Party (United States)|Republican]] [[Scott Brown (politician)|Scott Brown]] defeated [[Martha Coakley]] in the [[2010 United States Senate special election in Massachusetts|Massachusetts special election to the United States Senate]]. Coakley, a [[Democratic Party (United States)|Democrat]], had been widely expected to win, but Brown unexpectedly closed the gap and won, a shocking result in the heavily-Democratic state of Massachusetts. This eliminated the Democratic Party's [[Filibuster in the United States Senate|filibuster-proof]] majority of 60 votes. Another upset occurred in the [[2017 United States Senate special election in Alabama|2017 special election in Alabama]], one of the most heavily Republican states in the nation. Democrat [[Doug Jones (politician)|Doug Jones]] defeated Republican [[Roy Moore]] in a close race after Moore was [[Roy Moore sexual misconduct allegations|accused of sexual assault by multiple women]].