It was formed largely in opposition to rapid political success of the Mouvement Démocratique de la Rénovation Malgache (MDRM), a predominantly Merina pro-independence nationalist party.

While the MDRM and other nationalist parties enjoyed broad support across various ethnic communities, PADESM focused on empowering and ensuring fair governance for the historically marginalized coastal people which had a long history of conflict with the agrarian and caste-oriented Merina.

The nationalist Malagasy Uprising of 1947 led the French colonial administration to dissolve the MDRM and temporarily suspend all other political parties in Madagascar, including PADESM in spite of their previous support.

However, by December 1948 the uprising had been largely suppressed by colonial authorities, allowing PADESM to resume its political activities while the MDRM would be banned due to its involvement, with most of its leaders either imprisoned or killed in the conflict.

Many other major political figures in Madagascar have connections to the former PADESM, including former president Didier Ratsiraka and former prime minister Jacques Sylla.

Following the conclusion of the Second World War, a constituent assembly convened in Paris in November 1945 to draft the constitution of the French Fourth Republic.

Alongside the Malagasy Négritude writer Jacques Rabemananjara, whom they met in Paris, Raseta and Ravoahangy would found the Mouvement Démocratique de la Rénovation Malgache (MDRM) in Early 1946.

[2] The party's platform was built on national independence from France and garnered mass support that cut across geographic, ethnic and class divisions.

[4] Other founding members included Philibert Tsiranana (who became Madagascar's first president after independence), Albert Sylla (who became Minister of Foreign Affairs under Tsiranana, and whose son, Jacques Sylla, would go on to become Prime Minister of Madagascar under Marc Ravalomanana),[5] Albert Ratsiraka, and Pascale Velonjara, the latter two being father and father-in-law of future president Didier Ratsiraka respectively.

[8] Initially a non-nationalist party, PADESM eventually favored a gradual process toward independence that would preserve close ties to France and prevent the reemergence of the precolonial Merina hegemony.

[9] The French embraced PADESM's ethnic discourse, characterizing their support as an effort to champion the oppressed masses and protect them against exploitative Hova-Merina elites.

[11] In the January 1947 provincial elections, PADESM received financial support from French settlers[3] due to the party's favorable disposition to the colonial administration.

These factors finally erupted in a nationalist uprising that began on the evening of 29 March 1947[9] with attacks against a police camp and several French plantations in the eastern rainforest.

When Madagascar achieved independence in 1960, PSD leader Tsiranana was named the country's first president, a position he held until the rotaka protests forced him to resign in 1972.