Centrism is the range of political ideologies that exist between left-wing politics and right-wing politics on the left–right political spectrum. It is associated with moderate politics on the left-right spectrum, including people who strongly support moderate policies and people who are not strongly aligned with left-wing or right-wing policies. Centrism is commonly associated with liberalism, radical centrism, and agrarianism. Those who identify as centrist support gradual political change, often through the continuation of welfare state policies with moderate emphasis on redistributive policies. Though its placement is widely accepted in political science, radical groups that oppose centrist ideologies may sometimes describe them as leftist or rightist.
Centrist parties typically hold the middle position between major left-wing and right-wing parties, though in some cases they will hold the left-leaning or right-leaning vote if there are no viable parties in the given direction. Centrist parties in multi-party systems hold a strong position in forming coalition governments as they can accommodate both left-wing and right-wing parties, but they are often junior partners in these coalitions and are unable to enact their own policies. These parties are weaker in first-past-the-post voting than proportional representation systems. Parties and politicians have various incentives to move toward or away from the centre, depending on how they seek votes. Some populist parties take centrist positions, basing their political position on opposition to the government as opposed to left-wing or right-wing populism.
Centrism developed with the left–right political spectrum during the French Revolution, when assemblymen associated with neither the radicals nor the reactionaries sat between the two groups. Liberalism became the dominant centrist ideology in the 18th century, challenging both conservatism and socialism. Agrarianism briefly existed as a major European centrist movement in the late-19th and early-20th centuries. Centrism became more influential after the dissolution of the Soviet Union as it spread through Europe and the Americas, but it declined following the 2008 financial crisis, with an increase in populism and political polarization.
Ideology and political positions As with all ideological groups, the exact boundaries of what constitutes centrism are not perfectly defined; however, its specific placement on the left–right political spectrum makes its position clearer relative to other ideologies. The preferences of the median citizen are in the middle between opposing ideologies on the political spectrum. Centrism most commonly refers to a set of moderate political beliefs between left-wing politics and right-wing politics. Individuals who describe themselves as centrist may hold strong beliefs that align with moderate politics, or they may identify as centrist because they do not hold particularly strong left-wing or right-wing beliefs. In some cases, individuals who simultaneously hold strong left-wing beliefs and strong right-wing beliefs may also describe themselves as centrist. Although the left-centre-right trichotomy is well established in political science, individuals far from the political centre may occasionally reframe it, with the far-right alleging that the centre is leftist and the far-left alleging that the centre is rightist. Likewise, they may allege that their more moderate counterparts, the centre-left and the centre-right, are actually centrists because they are insufficiently radical.
Liberalism is by some associated with the political centre. Both left-leaning and right-leaning variants of liberalism may be grouped within a broader understanding of centrism. In Europe, left-leaning liberalism emphasises social liberalism and is more common in nations with strong conservative movements, while right-leaning liberalism emphasises economic liberalism and is more common in nations with strong Christian democratic movements. Social liberalism combines centrist economic positions with progressive stances on social and cultural issues.
Green parties, usually associated with left-wing politics, have a history of centrist economic policies in Central and Eastern Europe. Christian democracy, often considered a centre-right ideology, is sometimes grouped with the centre. Agrarianism may also be grouped with the centre. Agrarian parties are associated with the interests of farmers and other people associated with agriculture. Decentralization and environmental protection are also major agrarian ideals. These parties often developed in European countries where there was not a strong liberal movement, and vice versa, but they became less relevant by the mid-20th century.
Radical centrism is a form of centrism defined by its rejection of the left–right dichotomy or of ideology in general. Liberal scepticism and neo-republicanism can both be elements of radical centrism. Third Way politics is a radical centrist approach taken by centre-left parties to find a middle ground between capitalism and socialism. Though populism is commonly associated with strong left-wing or right-wing beliefs, centrist populism is critical of the political system independently of social, economic, and cultural issues. Centrist populist parties often do not have a strong ideological component, instead making anti-establishment politics the core of their message to capitalise on voter dissatisfaction and receive protest votes. These parties are most common in Central and Eastern Europe.
Centrism tends to advocate for gradual change within a political system. Support for a middle class is a defining trait of centrism, holding that it is preferable to reactionary or revolutionary politics. In some countries centrists support a liberal welfare state. Centrist coalitions are associated with larger welfare programs, but they are generally less inclusive than those organised under social democratic governments. Centrists may support some redistributive policies, but they oppose the total abolition of the upper class. Centrist liberalism seeks institutional reform, but it prioritises prudence when enacting change. European centrist parties can be in favour of European integration and were the primary movers in the development of the European Union. Whether political positions are considered centrist can change over time; when radical positions become more widely accepted in society, they can become centrist positions.
Political function Elections and retention of power In multi-party systems, the centre is challenged by parties that seek to undermine the legitimacy of the political system. These parties come from both the left and the right and have different positions on how the government should function, which prevents them from unifying against the centre, giving the centre an opportunity to retain power. According to the median voter theorem, in single-winner elections candidates are incentivised to move toward the political centre in order to win.
Centrist parties face some intrinsic disadvantages when competing with left-wing and right-wing parties. Elections based on first-past-the-post voting or proportional representation provide less incentive for parties to hold centrist positions. Proportional representation systems weaken centrist parties because they incentivise the capture of specific voters instead of the general population. The popularity of centrism in the Western World is contradicted by the relative electoral weakness of centrist parties. One possible explanation for the paradox is that centrists may be perceived as lacking the leadership or capability demonstrated by leaders of other ideologies. Another is that centrists are unable to increase their vote share because the ideological space around them is already occupied by other parties.
Politicians with high approval might move to the centre to capitalise on their popularity with a larger voter base, while those seen as uncharismatic or incompetent may shift away from the centre to capture more reliable activist voters who will invest more into the politician's campaign. Opponents of centrism may describe it as opportunistic. Centrist-controlled governments are much rarer than left-wing or right-wing governments. While approximately 30% of world leaders were centrist in the 1950s and 1960s, this declined to approximately 15% by 2020. Centrist dictatorships rarely occur.
Coalition building Most political party systems lean toward the centre, where centre-left and centre-right parties compromise with centrist parties. Centrist parties are typically found in the middle of a party system, leading to mixed use of the term centre to refer to centrist parties and to this middle position regardless of a party's ideological stance. Conversely, some centrist parties will only be challenged from one direction instead of facing both left-wing and right-wing challengers, preventing it from taking its typical location in the middle of a party system. What constitutes the middle of a political system is unique to each nation, while ideological centrism is a political stance that exists internationally.
Coalition building typically occurs around the political centre, giving centrist parties hold a position in the formation of coalition governments, as they can accommodate both left-wing and right-wing parties. This gives them additional leverage in the formation of a minority government. When radical parties become viable, forming a coalition with the centre can force them to moderate. Once in a coalition, the centrist party is typically a junior partner that has little ability to enact its own policy goals. Party systems with a strong centrist element are associated with lower interparty conflict.
Political polarisation The overall effect of centrist parties on a political system is a subject of debate in political science, and it is not always clear whether they encourage or discourage political polarisation, or whether they benefit or suffer from it. One unanswered question in political philosophy is whether centrist parties create centripetal or centrifugal party systems. When centrist parties exert a centripetal force on other parties, it causes left-wing and right-wing parties to move closer to the centre and creates political stability. Alternatively, they may exert a centrifugal force in which left-wing and right-wing parties move away from the centre to pressure the centrist party into choosing a side, causing political instability.
French political scientist Maurice Duverger argued that politics naturally drifts away from the centre into a two-party system and that a centrist party is an unnatural combination of the centre-left and centre-right. Italian political scientist Giovanni Sartori argued that centrism is the default in a political system, but that the existence of a centrist party prevents the left and the right from moving toward the centre and encourages polarisation. American economist Anthony Downs proposed a model in which a centrist party emerges after the left-wing and right-wing parties diverge from a centrist-leaning public. Dutch political scientist rejected the concept of a singular political centre entirely.
When parties become more extreme, disaffected moderates may be enticed to join centrist parties when they would otherwise have been unwilling to join an opposing party. More broadly, polarisation can lead to the fragmentation of the left and right into multiple parties, allowing a centrist party to perpetually be the Condorcet winner. Polarisation may also weaken a centrist party if both ends of a polarised society are made to oppose centrism.
Regional variation