It soon controlled its electoral and propagandistic structure, a fact that would influence the dominance of the Democratic Party during the First Republic.
During the First Republic, the Democratic Party, led by Afonso Costa, managed to hold power despite suffering several revolutionary attempts, both monarchist and republican.
Although some of the coups partially succeeded (Monarchy of the North, Pimenta de Castro, Sidónio Pais) the Democratic Party always managed to retain power.
After 1919, with Afonso Costa in Paris, the party was led by António Maria da Silva.
In the next phase of the party's existence, political, popular and syndicalist opposition created a climate of constant revolt.