The Senegal branch of the French Socialist Party (SFIO) won the first postwar elections largely because its leaders constituted the only organized party that had contacts in all parts of the colony. It sought to establish political and juridical equality between French and Senegalese citizens. In 1948, however, its leaders, Ahmadou Lamine-Guèye and Léopold-Sédar Senghor, quarreled. Senghor left the SFIO and founded a new party, the Senegalese Democratic Bloc (Bloc Démocratique Sénégalais—BDS), which was based more in the rural areas than in the old communes, from which Lamine-Guèye derived his political support. The new party emphasized social and economic rather than juridical issues and geared its program closely to peasant interests and grievances. In 1951, it won both Senegalese seats in the French National Assembly and, in 1952, 43 of the 50 seats in Senegal's Territorial Assembly.
In the French National Assembly, Senghor had meanwhile taken a leading part in creating a new parliamentary group, the Overseas Independents (Indépendants d'Outre-Mer—IOM), emphasizing African and colonial problems. It was, however, confronted by another African party, the African Democratic Rally (Rassemblement Démocratique Africain—RDA), founded in October 1946 by African deputies hostile to the provisions of the constitution of 1946 regarding the overseas territories. Although the RDA substantially reduced the number of seats held by the IOM in the French parliament, in Senegal it made no inroads on the two established parties, the BDS and the SFIO.
Senghor and his associate Mamadou Dia secured overwhelming majorities at the parliamentary elections in 1956 and launched a campaign to unite all Senegalese parties. They faced the opposition of Lamine-Guèye, who sponsored a first attempt to create an African Socialist movement loosely associated with the SFIO, and of the RDA leadership, which aimed at bringing about the unity of all parties within the RDA.
In 1956, Senghor's party, the BDS, was reorganized to become the Popular Senegalese Bloc (Bloc Popular Sénégalais), which took a strongly nationalistic stance. In the Territorial Assembly elections in 1957, the first held under complete universal suffrage, it won 47 seats, while the SFIO won only 12. Lamine-Guèye and Senghor were reconciled in 1958, and their respective parties fused in April 1958 to form the Senegalese Progressive Union (Union Progressiste Sénégalaise—UPS). The UPS supported the new French constitution in the referendum of September 1958, and in the elections to the Senegal legislature in 1959 it won all 80 seats. After independence in 1960, the UPS remained the dominant political party. President Senghor was its secretary-general, and the party's National Council was responsible for major national policy decisions. In 1976, the UPS changed its name to the Senegalese Socialist Party (Parti Socialiste Sénégalais—PS), after joining the Socialist International.
There was no legal opposition party from 1966 until 1974, when Abdoulaye Wade obtained permission from Senghor to create the Senegalese Democratic Party (Parti Démocratique Sénégalais—PDS). The PDS won 17 Assembly seats in 1978, compared with 83 for the PS.
In 1981, the constitution, which had restricted the number of political parties to four, was amended to end all restrictions. In 1982, the government amended the electoral law for the legislature so that half the deputies would be elected on a basis of proportional representation, while the remaining members were chosen by direct suffrage. This helped the regime win the 1983 presidential and legislative elections in which Diouf received 83.5% of the votes cast. Presidential and legislative elections held in 1988 were marred by rioting in cities and minor conflicts in rural areas, but Diouf officially received 73.2% of the votes cast.
Seven parties contested the National Assembly elections of 9 May 1993. The PS won 84 seats; the PDS won 27; the Jappoo Leggeeyal ("Let Us Unite") Party and the Democratic League won three seats each; the Independence and Labor Party (PIT) won two seats; and the Senegalese Democratic Union/Renewal party got one.
Although many people have lamented Senegal's "stalled" democratic transition, democrats may be encouraged by the growth of party competition. From 1983 to 1993, the PDS increased its share of representation in the Assembly from 8 to 27 seats, while the number of PS seats declined from 111 to 84. In presidential elections over the same period of time, Abdoulaye Wade's percentage of the vote climbed from 15% to 32%, while Diouf's dropped from 83% to 58%. The number of officially recognized parties in Senegal has gone from one in 1973 to 26 in 1997. From 1978 to 1996, the number of parties contesting legislative elections went from 4 to 14.
In the February–March 2000 presidential elections, eight parties presented candidates. Diouf's PS enjoyed the support of several tiny parties, and a coalition of four parties known as the Convergence Patriotique (CP). The CP comprised the Bloc des Centristes Gainde (BCG) led by Jean-Paul Dais, the Parti Liberal Senegalais (PLS), led by Ousmane Ngom, Serigne Diop's Parti Démocratique Sénégalais-Renovation (PDS-R), and the Parti Africain de l'Indépendence (PAI) of Majmouth Diop. The PAI was once Marxist, while the three others emerged from splits in the PDS. On the other hand, Wade's PDS claimed the backing of the Pole de Gauche, a left-wing coalition of the And-jeff/Parti Africain pour la Démocratie et le Socialisme (AJ/PADS), and the Ligue Démocratique-Mouvement Travail (PIT).
However, the real difference in the outcome of the 19 March second round was the support of Moustapha Niasse (AFP) and to a lesser extent, Djibo Ka (URD), both defectors from the PS who formed their own parties. President Wade's subsequent appointment of Mr. Niasse as his prime minister all but confirmed that Mr. Niasse's supporters believed they were voting for a Wade-Niasse ticket. On the first round, Diouf obtained 41%, Wade 30%, Niasse 17%, Ka 7%, with four other candidates picking up the remaining 4% of the vote. Wade's second round alliance gave him an easy victory over Diouf with 58.5% of the vote.
The most recent parliamentary elections were held 29 April 2001 giving Wade's SOPI coalition an overwhelming victory with 89 seats to 11 for the AFP, 10 for the PS, and 10 for other parties. In the municipal and local elections 12 May 2002, Wade's coalition, the Convergence des actions autour du Président en perspective du 21ème siècle (CAP 21) captured a majority of the 433 posts. The opposition joined forces under the Cadre Permanent de Concertation (CPC), which included the Parti de l'indépendence et Travail (PIT), the Parti Socialiste (PS), the Union pour le Renouveau Démocratique (URD), and Alliance des Forces de Progrès (AFP). They attacked the government for failing to privatize the electric utility, for bungling groundnut sector reforms, and for mishandling relations with unions and multi-lateral lending institutions.