Under the Third Republic, the majority of the AD's deputies sat in the Left Republicans (Républicain de Gauche) group,[7] the main centre-right parliamentary formation (due to a particularity called sinistrisme right-wing politicians took some time to accept the label 'right-wing', as republicanism was traditionally associated with the left-wing and the right-wing traditionally meant some form of monarchism: see Legitimist and Orléanist).
During the same period, the Alliance operated a shift to the right on the political spectrum and ended the policy of mutual withdrawals with the Radical-Socialists in electoral runoffs.
The experience was not successful because the Alliance became a prisoner of the right which constituted the bulk of the parliamentary majority, thus the failure of Aristide Briand cabinet (1921–1922) convinced its leaders to find practical ways to realize the doctrine of the just-middle despite the fact that one of its members, Raymond Poincaré, occupied the post of President of the Council between 1922 and 1924.
Nevertheless, the Alliance could not get the Radicals to rally around a centrist party, the opposition crystallizing around the issue of secularism, the intervention of the state or in terms of foreign policy (contrast between Aristide Briand and Raymond Poincaré).
Pierre-Étienne Flandin took the chair of the Alliance in 1933 with the aim to reorganize the party in a way which Louis Marin had done ten years earlier with the Republican Federation.
It became on the contrary a party which showed the different opinions chosen by the men from the Republican and parliamentary rights to address the social and political crises of the thirties.
Unlike the Rad-Soc doctrine, it aspired to unite all Republicans and to impose the right and left a third way, that of the combination of centers around the phrase "no reaction nor revolution".
The theme of gradual reform was seen by the Alliance as the antidote to the opponents of the Republic, that is the collectivists (the French Section of the Workers' International and the French Communist Party) Its creation reflects the will to oppose the polarization due to the progressive division during the Dreyfus affair and impose a three-party system leading to the Republic of the just-middle theorized by François Guizot.
The ARD was created by the progressives who supported Captain Alfred Dreyfus and opposed those who followed Jules Méline in opposition to the President of the Council Pierre Waldeck-Rousseau.
Even if the party's principal leaders were often related to business, the majority of its elected officials opposed the wishes of businessmen, in particular on social policies.