In historiography political antecedents of Daniel are summarized as "scarcely homogeneous". Some of his paternal uncles engaged in Tafallese militia and ancestors of his wife were distinguished Estella Liberals. It is clear, however, that the Carlist leaning prevailed; apart from Daniel's father and other paternal uncles also his maternal uncle, Sebastián Urra Jordán, held various posts in the party and represented it in the Cortes. As it was him appointed by late Manuel cabezalero of his children, Urra has contributed to their Carlist outlook. Already as a child in Carlist-held Estella Daniel used to collect unexploded cartridges fired by the governmental troops to make sure they do not hurt the Carlists, and he admitted to having "sucked" Carlism when a child. Education in Orduña college, managed by the Jesuits, is likely to have reinforced this stand; also during academic years in Valladolid Irujo remained in the company of Carlism-minded friends.