[1][2] Its founders were from two main groups, one of lawyers and private sector workers, and the other of intellectuals supportive of social democracy.
[2] In March 1990 internal tensions led to the party splitting into two factions, PSD-I and PSD-II.
Together the factions received 1.1% of the vote in the 1990 local elections, winning 65 seats and gaining control of two Popular Communal Assemblies.
[3] Under pressure from the Ministry of the Interior, the two factions were reunited after a meeting in January 1991.
[3] In the 1991 parliamentary elections, the PSD received 0.4% of the vote, failing to win a seat, although the results were later annulled.