His Orleanist tendencies and his objections to the republic were strong, and though he at first supported Tillers, he afterwards became a leader of the opposition to the president.
In 1866 he was employed at the ministry of war in the preparation of army reorganization schemes, and he published anonymously in the following year L'Armee francaise en 1867, a work inspired with Orleanist sentiment, which ran through ten editions in a few months and reached a twentieth in 1870.
Elected a member of the National Assembly in 1871, he zealously supported the Orleanist party.
A few more military disasters, royalist insurrections in the south, Chouan disturbances in Normandy, Orleanist intrigues and the end came.
The execution of his father in November 1793 had made him duke of Orleans, and he now became the centre of the intrigues of the Orleanist party.
The struggle was now between the two branches of the royal family, the Orleanist and the Burgundian, between the aristocratic south and the democratic north; while the Siggle deposition of Richard II.
Freycinet's cabinet, he erased the name of the duc d'Aumale from the army list, as part of the republican campaign against the Orleanist and Bonapartist princes.