|Part of the Politics series|
An electoral wipeout occurs when a major party receives far fewer votes or seats in a Legislature than their position justifies. It is the opposite of a landslide victory; the two frequently going hand in hand.
Note that the use of the phrase generally assumes that the returns were the product of a legitimate election; show elections to fraudulent legislatures regularly produce incredibly strong majorities for the ruling party(s).
Between 1901 and 1949, the upper house of the Australian Senate was elected by a system of majoritarian or "winner-take-all" voting. Each state had 3 of its 6 Senators retiring at each half-senate election. Each voter had 3 votes at each election, whether by first-past-the-post (FPTP) 1901-1918, or the alternative vote. It was often the case that the 3 seats all went the same way, leading to lopsided results in the six states such as 36-0 or 3-33. These results brought the parliament into some disrepute.
In 1948, the Single Transferable Vote (STV) was introduced. At the same time, the number of senators per state was increased from 6 to 10, with 5 instead of 3 retiring at each triennial election. The increased number of vacancies per election would have exacerbated the "landslide/wipeout" effect if the old winner-take-all system had been retained. Instead, having more seats increased the degree of proportionality between votes received and seats won by parties.
Since the introduction of STV in the Senate, the parties have generally been evenly balanced, with minor parties and independents holding the balance of power. While frustrated, the government in the lower house has had a lot of different people to negotiate with.
In the 2004 election, the government did the nearly impossible and gained the 57% of the vote in one state to obtain a majority in its own right in the senate from July 2005, when the new senators take up their seats. The number of quotas required to win a majority (four) of six seats, at 57% (four-sevenths of the votes), is so high because there are an even number of seats.
In the lower house, FPTP was changed to preferential voting in 1918.
In the 1974 Queensland state election, using single-member electorates and full-preferential voting, the Labor opposition was reduced to a "cricket team" of eleven MPs, against the National Country Party/ Liberal Party Coalition government with 69 seats (and 2 Independents).
- In the Canadian federal election, 1993, the governing Progressive Conservative Party was reduced from a strong majority government to only two seats.
- In the Canadian federal election, 2011, the Bloc Québécois was reduced to 4 seats.
- In the Canadian federal election, 2015, the Liberals won all seats in the Atlantic Provinces.
- In the British Columbia general election, 2001 the governing NDP was reduced to two seats, with the other 77 being won by the Liberals.
- New Brunswick general election, 1995 51.6% - 30.9% 48 - 7 (wipe out)
- New Brunswick general election, 1991 47.1% - 21.2% 46 - 8-3-1 (lop-sided)
- New Brunswick general election, 1987 60.4% - 28.6% 55 - 0 (clean sweep)
- Ontario general election, 1987 47.3% 25.7% - 95 - 19 - 16 (lopsided)
- Prince Edward Island general election, 2003 54.0% 42.9% - 23 -4 (wipe out)
- Prince Edward Island general election, 2000 57.9% 33.7% - 26 -1 (wipe out)
- Prince Edward Island general election, 1996 47.8% 44.8% - 18 -8 - 1 (strong government; strong opposition)
- Prince Edward Island general election, 1935 51.7% 48.3% - 30 -0 (wipe out)
- Saskatchewan general election, 1991 51.1% - 25.5% 55 - 10 - 1 (lopsided)
- Saskatchewan general election, 1982 54.1% - 37.6% 55 - 9 (wipe out)
- Saskatchewan general election, 1944 53.1% - 35.4% 47 - 5 (wipe out)
- Saskatchewan general election, 1934 48.0% - 24.0% 50 - 5 (wipe out)
Until it moved to a proportional representation system in 1996, general elections in New Zealand were also prone to the possibility of wipeouts, though these in general involved the likelihood of third parties getting few or no seats rather than one of the two major parties being massively underrepresented. This former circumstance occurred most starkly in the 1981 general election, in which the Social Credit Party gained 16.1% of the vote yet gained only two seats in the 92-seat parliament.
The 1935 general election did, however, see a major party wipeout, and led to the creation of a new major party. In the 1935 election, the Labour Party gained 46.1% of the vote to the United/Reform Coalition's 32.9%, but won 53 seats to the United/Reform's 19. As a result of this election the two coalition parties merged to form the National Party, which remains a major force is current New Zealand politics.
- In the United Kingdom general election, 1997, the Conservative Party were wiped out in Scotland and Wales - losing eleven and six seats respectively. The Conservatives failed to pick up a seat in Wales in the 2001 election either. The Conservatives picked up a seat in Scotland in 2001, but they haven't gained any additional MPs since then, while their share of the vote has remained below 20%.
The Scottish Parliament elections uses a version of the Additional member system, meaning that 73 seats are won through First Past the Post constituency votes, and additional seats are added for the regional vote which uses a variation of the D'Hondt method.
- In the Scottish Parliament general election, 2007, the Socialists lost all of their six seats, with their share of the vote reduced by over 6%.
- In the Scottish Parliament general election, 2011, Labour lost twenty constituency seats (seven overall), with the Liberal Democrats losing nine (twelve overall). The Lib Dems were left with only two constituency seats, suffering a complete wipeout on the Scottish mainland, leaving only Shetland and Orkney (two of the safest seats in the country) with Lib Dem MSPs.
- Philippine Senate election, 1955: With the 24-seat Senate of the Philippines elected via nationwide plurality-at-large voting (8 votes per voter) and on staggered elections, the Liberal Party's seven seats were lost when none of their candidates finished eighth place or higher, despite having 29% of the vote. After the election, the Nacionalista Party then had 21 seats, and two minor parties having 3 seats with one seat vacant.
- In the 2000 Mongolian State Great Khural Election, the Mongolian People's Revolutionary Party overturned a large majority for the Democratic Union, winning 72 out of the 76 seats contested.
1.  Singapore's Constituency Boundary Map