Two-party system
Third parties, meaning a party other than one of the two dominant parties, are possible in two-party systems, but they are often unlikely to exert much influence by gaining control of legislatures or by winning elections. While there are occasional opinions in the media expressed about the possibility of third parties emerging in the United States, for example, political insiders such as the 1980 presidential candidate John Anderson think the chances of one appearing in the early twenty-first century is remote. A report in "The Guardian" suggested that American politics has been "stuck in a two-way fight between Republicans and Democrats" since the Civil War, and that third-party runs had little meaningful success.
Dominant-party system
Sub-national entities are often dominated by one party due the area's demographic being on one end of the spectrum. For example, the current elected government of the District of Columbia has been governed by Democrats since its creation in the 1970s, Bavaria by the Christian Social Union since 1957, Madeira by the Social Democrats since 1976, and Alberta by Progressive Conservatives 1971–2015. On the other hand, where the dominant party rules nationally on a genuinely democratic basis, the opposition may be strong in one or more subnational areas, possibly even constituting a dominant party locally; an example is South Africa, where although the African National Congress is dominant at the national level, the opposition Democratic Alliance is strong to dominant in the Province of Western Cape.
Federally, a multi-party system exists, although only two federal parties have ever held power, the Conservative Party and the Liberal Party. However, in some provinces, a party holds hegemonic status over all other parties.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 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.