The leading party of the right in El Salvador is the National Republican Alliance (Alianza Republicana Nacionalista—ARENA), organized in 1982 by Roberto D'Aubuisson. ARENA controlled the National Assembly until 1985, and its next leader, Alfredo Christiani, was elected to the presidency in 1989. Five years later, ARENA candidate Armando Calderón Sol became president. In the March 1997 parliamentary elections, ARENA's representation was reduced from 42 seats in the 84-member legislature to 28. In 1999, ARENA recovered and won the presidency again with 51.4% of the vote, but a year later its support fell to 36% in the National Assembly elections of March 2000.
The Chapultepec Accords introduced a new force into El Salvador's electoral system: the Farabundo Martí National Liberation Front (Frente Farabundo Martí de Liberación Nacional—FMLN). Named for an insurgent leader of the 1930s, the FMLN was originally a paramilitary group in armed rebellion against the government. As part of the 1992 accords, the FMLN is now a legal party after having ceased its military operations. The FMLN-backed candidate, Ruben Zamora, was the runner-up in the 1994 presidential election, winning 24% of the vote. In the March 1997 legislative elections, the FMLN made significant gains, nearly doubling its representation in the Legislative Assembly, from 14 to 27 seats, and winning municipal elections in half the departmental capitals. In the March 2000 elections, the FMLN won 31 seats, shy of a majority but more than any other political party. In 2003, the FMLN increased its share of the vote to 34%, but did not win any additional seats in parliament.
The moderate Christian Democratic Party (Partido Demócrata Cristiano—PDC) was formed in 1960. For three decades, it was associated with its leader and founder, José Napoleón Duarte. Damaged by many splits over the years, and suffering after Duarte's unsuccessful presidency (1984–1989), the centrist PDC has lost strength among the electorate. In the most recent National Assembly elections in March 2000, it obtained 7.2% of the votes and 6 seats in the 84-member Assembly. In 2003, its share of the vote fell to 7.3% and it lost one seat. The National Conciliation Party (PCN), which was founded by the military in 1961, obtained 8.8% of the votes in the 2000 election and secured 13 seats, enough to give a majority to either ARENA or the FMLN. In 2003, it increased its vote to 13% and it secured 16 seats. Because of its ability to break the tie between the FMLN and ARENA, the PCN has gained an important negotiating role in Salvadorian politics. Since 2000, the PCN has mostly aligned with ARENA, allowing president Flores to command majority support in the legislature.
In March 2003, the Centro Democrático Unido (United Democratic Centre, social-democratic) secured 5 seats in the National Assembly.