[[File:Obelisco Buenos Aires Argentina.jpg|right|thumb|Obelisco by night, Buenos Aires.]]
The two largest political parties are the Justicialist Party (PJ—also called Peronist), founded in 1945 by Juan Domingo Perón, and the Union Civica Radical (UCR), or Radical Civic Union, founded in 1891. Traditionally, the UCR has had more urban middle-class support and the PJ more labor support, but both parties have become more broadly based. The PJ does not currently have a recognized national committee or leader due to internal differences. President Kirchner, a Peronist by origin, nominally is head of his Frente Para la Victoria (FPV) coalition that includes Peronists and non-Peronists aligned with him. Kirchner announced in July 2007 that he would not run for reelection in presidential elections in October 2007, and publicly supported the candidacy of his wife, Senator Cristina Fernandez de Kirchner. Fernandez de Kirchner formally announced her campaign for the presidency in July.
While the national leadership of the UCR remains in opposition to the Kirchner government, many of its governors, mayors, and other representatives have allied with President Kirchner. In the April 2003 presidential elections, the UCR received only 2% of the national vote, the lowest tally in the party's history. The UCR continues to retain significant strength in many parts of the country, and persons identifying with the party govern roughly one-third of the provinces. The UCR is the only opposition political party with a nationwide structure.