A dominant-party system, or one-party dominant system, is a system where there is "a category of parties/political organisations that have successively won election victories and whose future defeat cannot be envisaged or is unlikely for the foreseeable future." Many are de factoone-party systems, and often devolve into de jureone-party systems. Usually, the dominant party consistently holds majority government, without the need for coalitions.
Opponents of the "dominant party" system or theory argue that it views the meaning of democracy as given, and that it assumes that only a particular conception of representative democracy (in which different parties alternate frequently in power) is valid. One author argues that "the dominant party 'system' is deeply flawed as a mode of analysis and lacks explanatory capacity. But it is also a very conservative approach to politics. Its fundamental political assumptions are restricted to one form of democracy, electoral politics and hostile to popular politics. This is manifest in the obsession with the quality of electoral opposition and its sidelining or ignoring of popular political activity organised in other ways. The assumption in this approach is that other forms of organisation and opposition are of limited importance or a separate matter from the consolidation of their version of democracy."
One of the dangers of dominant parties is "the tendency of dominant parties to conflate party and state and to appoint party officials to senior positions irrespective of their having the required qualities." However, in some countries this is common practice even when there is no dominant party. In contrast to one-party systems, dominant-party systems can occur within a context of a democratic system. In a one-party system other parties are banned, but in dominant-party systems other political parties are tolerated, and (in democratic dominant-party systems) operate without overt legal impediment, but do not have a realistic chance of winning; the dominant party genuinely wins the votes of the vast majority of voters every time (or, in authoritarian systems, claims to). Under authoritarian dominant-party systems, which may be referred to as "electoralism" or "soft authoritarianism", opposition parties are legally allowed to operate, but are too weak or ineffective to seriously challenge power, perhaps through various forms of corruption, constitutional quirks that intentionally undermine the ability for an effective opposition to thrive, institutional and/or organizational conventions that support the status quo, occasional but not omnipresent political repression, or inherent cultural values averse to change.
In some states opposition parties are subject to varying degrees of official harassment and most often deal with restrictions on free speech (such as press laws), lawsuits against the opposition, and rules or electoral systems (such as gerrymandering of electoral districts) designed to put them at a disadvantage. In some cases outright electoral fraud keeps the opposition from power. On the other hand, some dominant-party systems occur, at least temporarily, in countries that are widely seen, both by their citizens and outside observers, to be textbook examples of democracy. An example of a genuine democratic dominant-party system would be the pre-EmergencyIndia, which was almost universally viewed by all as being a democratic state, even though the only major national party at that time was the Indian National Congress. The reasons why a dominant-party system may form in such a country are often debated: supporters of the dominant party tend to argue that their party is simply doing a good job in government and the opposition continuously proposes unrealistic or unpopular changes, while supporters of the opposition tend to argue that the electoral system disfavors them (for example because it is based on the principle of first past the post), or that the dominant party receives a disproportionate amount of funding from various sources and is therefore able to mount more persuasive campaigns. In states with ethnic issues, one party may be seen as being the party for an ethnicity or race with the party for the majority ethnic, racial or religious group dominating, e.g., the African National Congress in South Africa (governing since 1994) has strong support amongst Black South Africans and the Ulster Unionist Party governed Northern Ireland from its creation in 1921 until 1972 with the support of the Protestant majority.
Presidential election, 1992: dos Santos (MPLA-PT) won 49.6% of the vote. As this was not an absolute majority, a runoff against Jonas Savimbi (40.1%) was required, but did not take place. Dos Santos remained in office without democratic legitimacy.
New constitution, 2010: popular election of president abolished in favour of a rule that the top candidate of the most voted party in parliamentary elections becomes president.
As a whole, the nation has a two-party system, with the main parties since the mid-19th century being Democratic Party and the Republican Party. However, some states and cities have been dominated by one of these parties for up to several decades. Generally, the Democratic Party dominate in the urban metropolitan areas, while the Republican Party dominate in the rural areas. Following the 2018 elections, the Republican Party continued to hold a majority of State Legislatures and a majority of Governorships. However the Democratic Party won a majority of seats in the House of Representatives, while the Republican Party increased their majority in the Senate, resulting in a split Congress. As a consequence of Donald Trump's victory in the 2016 elections, the Republican Party also controls the Presidency.
Dominated by the Democratic Party:
California had a Republican governor as late as 2011 but has voted for Democrats in national races and has a legislature dominated by the Democrats since the 1990s. Due to the top two primary election, many statewide and local races are contested by two members of the Democratic Party in the general election.
Illinois has been governed under a Democratic super-majority in both houses of the legislature and the governorship since the 2018 elections. Chicago, has been historically dominated by the Cook County Democratic Party – the office of mayor has been filled by a Democrat continuously since 1931.
Oregon, while once a heavily Republican state, has had only one Republican governor since 1975, has voted Democrat in every Presidential election since 1988, and had no Republican statewide elected officials from 2002 until the election of Dennis Richardson as Oregon Secretary of State in 2016.
Idaho has been dominated by Republicans for most of its existence, with no Democratic governors since 1994 and only two years in which the State Senate was tied evenly since 1960.
Kansas has been dominated by Republicans for most of its existence, with only four years of Democratic majorities in the State House of Representatives since 1915 and only Republican majorities in the same period. Since 1967, however, five of the last nine governors have been Democrats, although one of these Democrats only held office for two years.
Louisiana is dominated by the Republicans. New Orleans, however, has been dominated by the Democratic Party since the 19th century.
Nebraska has been dominated by Republicans for most of its existence, with a non-partisan legislature (where a de facto Republican majority has held since records began in 2007), mostly Republican governors and elected cabinet officials and only one Republican who changed party to Democrat in 2006 holding state-level partisan office since 1999.
South Dakota has been dominated by Republicans for most of its existence, aside from a few Democratic and Populist governments and coalitions with Republicans, with only three elected high officials and two years of State Senate dominance since 1979.
Wyoming has been dominated by Republicans for most of its existence, with only four years where a house of the legislature has been Democratic since 1939, and mostly Republican governors during that period.
Dominant-party systems can also exist on native reservations with republican forms of government. The Seneca Nation of Indians, a tribe with territory within the bounds of New York State, has had the Seneca Party as the dominant party in its political system for several decades.
In power since 1946, with a sole hiatus from 1954 to 1958. From 1966 to 2003 and 2013 to 2018, CSU ruled with an absolute majority. Its share of votes peaked in 1974 at 62%. From 2003 to 2008, CSU held a two-thirds supermajority in the Bavarian Landtag. Since the 2010s, the CSU's dominance has somewhat eroded (38.8% in the 2017 German federal election; 37.2% in the 2018 Bavarian state election), but it is still considered impossible to form a government led by another party in Bavaria.
In power since the establishment of the state in 1990. CDU ruled with an absolute majority until 2004, and even a two-thirds supermajority in the Landtag from 1994 to 2004. Its popularity peaked at 56,9% in the 1999 election. In the 2010s, CDU's dominance eroded significantly. In the 2017 German federal election, Saxony's CDU came in second place for the first time in the history of the state, reaching 26.9%, behind the far-right Alternative für Deutschland. Due to the irreconcilability of left-wing and right-wing opposition parties, it is still considered impossible to form a state government led by another party than CDU.
Canada: The Liberal Party of Canada was the dominant party in the federal government of Canada for so much of its history that it is sometimes given the moniker "Canada's natural governing party". The party ruled for most of the 20th century between 1935 and 1984 (the only exceptions being in 1957–1963 and 1979–1980), as well as 1896–1911, 1921–1930 (save a few months), and 1993–2006, with a total of 80 years governed in the past 120 years (As in 2018). After a decade in opposition, the Liberals have returned to power following the 2015 election.
Nova Scotia: The Nova Scotia Liberal Party, in the Province of Nova Scotia, held office in an unbroken period from 1882 to 1925. During the period from 1867 to 1956, the party was in power for 76 of 89 years, most of that time with fewer than 5 opposition members.
Ontario: The Progressive Conservative Party of Ontario, in the Province of Ontario, held office uninterrupted from 1943 to 1985 (with minority parliaments from 1943 to 1945 and 1975 to 1981). And the Ontario Liberal Party, held power uninterrupted in Province's early history and occasional hiccups in later its history from 1871 to 1905, again in 1932 to 1943, 1985 to 1990, and 2003 to 2018 periods prior to its collapse (with minority parliaments from 1985 to 1987 and 2011 to 2014).
Quebec: The Union Nationale, in the Province of Quebec, held office uninterrupted from 1944 until 1960 with Quiet revolution. And nearly with the Quebec Liberal Party throughout province's political history with start from 1897 to 1935, then a second time in 1985 and 1989, and lastly third time in 2003 and 2008 periods.
The South (usually defined as coextensive with the former Confederacy) was known until the era of the civil rights movement as the "Solid South" due to its states' reliable support the Democratic Party, which at that time had a strong conservative wing. Several states had an unbroken succession of Democratic governors for half a century to over a century.
Nicaragua: The Partido Liberal Nacionalista of the Somoza family held effective control from the 1930s to 1979. It was never the sole legal party, but elections were often fraught with accusations of fraud and improbable results. Later the conservative government held effective control from 1990 to 2007.
Baden-Württemberg: The Christian Democratic Union of Germany ruled from 1953 to 2011 (in Baden and in Württemberg-Hohenzollern ruled the BCSV/CDU 1947–1952 and in Württemberg-Baden 1947–1951) and was biggest party until 2016 (except in Württemberg-Baden for 1950–1952), but is still biggest party at German federal elections and European Parliament elections. And in Baden was the Centre Party in Weimar republic biggest party until 1930.
Bayern: The Christian Social Union in Bavaria held majority in the Landtag of Bavaria from 1966 to 2008 with the best vote share in 2003 (60.6% and 124 of 180 seats). The party lost its majority in the 2008 elections and governed in a coalition alongside the FDP before regaining its majority in 2013. However, this majority was once again lost in the 2018 state election.
Saarland: The Christian Democratic Union of Germany and his predecessors ruled from 1919 to 1980. In Landatg elections, the CDU, the SVP, the CVP and the CSU-S together reached between 47.8% in 1955 and 54.7% in 1952, in Landesrat elections, the Center Party reached between 42.8% in 1924 and 47.7% in 1922, in the Election to the German National Assembly reached Z/BVP 47.0%, in the 1935 Saar status referendum came the election recommendation of the German Front to 90.73%, in federal elections dominated the CDU/CSU (except for 1972) and in the European election 1979 won the CDU/CSU with 46.4%.
Luxembourg: The Christian Social People's Party (CSV), with its predecessor Party of the Right, governed Luxembourg continuously since 1915 until 2013, except for 1974–1979. However, Luxembourg has a coalition system, and the CSV has been in coalition with at least one of the two next two leading parties for all but four years. It has always won a plurality of seats in parliamentary elections, although it lost the popular vote in 1964 and 1974.
Portugal: The Portuguese Republican Party, during most of the Portuguese First Republic's existence (1910–1926): After the coup that put an end to Portugal's constitutional monarchy in 1910, the electoral system, which had always ensured victory to the party in government, was left unchanged. Before 1910, it had been the reigning monarch's responsibility to ensure that no one party remain too long in government, usually by disbanding Parliament and calling for new elections. The republic's constitution added no such proviso, and the Portuguese Republican Party was able to keep the other minor republican parties (monarchic parties had been declared illegal) from winning elections. On the rare occasions when it was ousted from power, it was overthrown by force and was again by the means of a counter-coup that it returned to power, until its final fall, with the republic itself, in 1926.
Sweden: The Swedish Social Democratic Party in Sweden from 1932 to 2006 except only for some months in 1936 (1936–1939 and 1951–1957 in coalition with the Farmers' League, 1939–1945 at the head of a government of national unity), 1976-1982 and 1991-1994. The party is still the largest party in Sweden and has been so in every general election since 1917 (hence the largest party even before the universal suffrage was introduces in 1921). The former Prime minister and party leader Tage Erlander led the Swedish government for an uninterrupted tenure of 23 years (1946–1969), the longest in any democracy so far. Since 2006 the party support has declined.
United Kingdom: The Conservative and Unionist Party held power alone or as the largest coalition partner from 1916 to 1923, from 1924 to 1929, from 1931 to 1945, from 1951 to 1964, from 1970 to 1974 and from 1979 to 1997 – in total 61 out of 81 years from 1916 to 1997.
Israel: Mapai in Israel was the dominant party from the establishment of the state of Israel in 1948 until merging into present-day Israeli Labor Party in 1968. The Labor Party started losing influence in the 1970s, particularly following the Yom Kippur War, and eventually lost power in the 1977 election. The Labor Party continued to participate in several coalition governments until 2009.
Australia: The Liberal Party (generally in coalition with the National Party) held power federally from 1949 to 1972 and from 1975 to 1983 (31 out of 34 years). By the scheduled expiry of the 46th Parliament in 2022, the Liberal-National Coalition will have held power for 20 out of the 26 years between 1996 and 2022.
^Grétar Thor Eythórsson, Detlef Jahn (2009), "Das politische System Islands", Die Politischen Systeme Westeuropas (in German) (4., aktualisierte und überarbeitete ed.), Wiesbaden: VS Verlag für Sozialwissenschaften, p. 200, ISBN978-3-531-16464-9