Why did the struggle for the political structure of France end in victory for the Republicans?

The political structure in France in the first half of the 20th century remained unchanged, but because of the world aspiration for radical movements, socialists and fascists appeared in this state as well. A fierce struggle was fought for seats in parliament, but as a result of the political struggle, the revolutionary movements were suppressed, and the republicans won the country. This form of government characterized the structure of the state. The supporters of this form of government carried out reforms that had a positive effect on development.