Since the end of the War of the Triple Alliance, two parties have dominated politics—the National Republican Association (Asociación Nacional Republicana), generally known as the Colorado Party, and the Liberal Party. Both parties have exemplified the uncompromising nature of Paraguayan politics and used their position to stifle the opposition. Consequently, changes of administration have been effected principally by armed revolt.
The Colorado Party governed from its founding in 1887 until 1904, and again after 1947. Conservative and nationalistic, the Colorados split during the 1950s into two factions: the "officialist" Colorados supported the Stroessner dictatorship, while the People's Colorado Movement (Movimiento Popular Colorado—MOPOCO) styled itself a supporter of "representative democracy." Most of the MOPOCO leadership chose exile in 1959. In the 1980s the Colorados became even more divided. Three groups emerged: a "militant" pro-Stroessner faction; "traditionalists," pushing for Stroessner to step down; and a reformist "ethical" faction, which is interested in cleaning up government corruption.
The 1989 coup was engineered by a leader of the "traditionalist" faction. Wasmosy, the first freely elected civilian president, who took office in 1993, was more reformist in his approach. Raúl Cubas was elected party president in 1998. He ran against his fellow party member President Wasmosy and was supported by General Lino Oviedo, who had attempted a military coup against Wasmosy in 1995. After the assassination of Colorado Party vice president Luis Argaña in 1999, Cubas had to resign. Senate president Luis González, also from the Colorado Party, became president. González faced accusations of corruptions but an effort to impeach him failed in 2002. Even with the hefty parliamentary majority—45 out of 80 seats in the Chamber and 24 out of 45 seats in the Senate—the Colorados remained badly split and in disrepair until 2003. That year, the Colorado Party only won 37 seats in the Chamber and 16 seats in the Senate, falling short of a majority control in either chamber.
The Liberal Party, like the Colorados, appeared in 1887. They seized power in 1904 and governed until 1936. Banned in 1942, the Liberals were reconstituted during the 1960s. There has never been a recognizable ideological distinction between the Liberals and Colorados, but the two parties are similar in their disunity. Liberals had, by 1982, split into three factions: the Authentic Radical Liberal Party (Partido Liberal Radical Auténtico—PLRA), the Liberal Teeté Party (Partido Liberal Teeté—PLT), and the Radical Liberal Party (Partido Liberal Radical—PLR). After 1989, the PLRA and the PLR reemerged to compete for votes, with the PLRA considerably stronger. The PLRA, led by Domingo Laíno, was the largest opposition party in 1996. In the 1998 presidential and parliamentary elections Laíno obtained 43.9% of the vote and his party secured 27 out of 80 seats in the Chamber of Deputies and 13 out of 45 seats in the Senate. The 2003 presidential candidate, Julio César Franco obtained a disappointing 24% of the vote, and the Liberal Party secured 21 seats in the Chamber and 12 seats in the Senate.
A new party, National Encounter (PEN), was formed in recent years. It consists of an alliance of several smaller parties and civic organizations and appeals to the urban middle class. The PEN won eight seats in the Senate and nine seats in the Chamber of Deputies in the 1993 elections. But in 2003, it failed to win seats in either chamber. In 2003, three smaller parties, the populist Movement Fatherland of the Best, the conservative National Union of Ethical Citizens and the leftwing Party for a Country of Solidarity also won 10, 10 and 2 seats respectively in the Chamber and 8, 7 and 2 seats respectively in the Senate in 2003.
Electoral reform has purged the voter rolls of the deceased (who usually "voted" for Colorado Party members), made voting more than once in an election a punishable crime, and established a tribunal to oversee the electoral process. These reforms appear to be working so far, as evidenced by fair municipal elections in 1996 and presidential and parliamentary elections in 1998 and 2003.