[4] It is the only Sammarinese party with a reference to the European Union in its official political symbol.

Another split in 2009 in Borgo Maggiore formed the Sammarinese Reformist Socialist Party.

For the 2008 general election the PSD allowed the smaller Sammarinese for Freedom party run as part of its electoral list and was part of the Reforms and Freedom electoral coalition which won 25 seats out of 60 in the Grand and General Council gaining 45.78% of the national vote but failed to gain a governmental majority and as a result the Party of Socialists and Democrats which itself gained 18 seats (a few of which went to Sammarinese for Freedom) out of the 25 the coalition gained and 31.96% of the national vote, and became part of the official opposition to the government of the centre-right coalition Pact for San Marino.

For the 2012 general election, the PSD ran as part of the winning San Marino Common Good coalition led by the Sammarinese Christian Democratic Party, restoring the political formula which had run San Marino until the 1990s.

In April 2024 the party launched an alliance with the PS and Libera San Marino for the 2024 general election,[5][6] referred to as the Liberal/PS–PSD coalition.