Since 1932 Casariego worked for a conservative daily "La Nación", running the crónica política column and acting as a correspondent; around the same time he started contributing to the central Madrid Carlist daily "El Siglo Futuro", initially as an Oviedo correspondent and since 1936 as member of the editorial board. He covered the Asturian Revolution and recognized as reactionary journalist, in Madrid was subject to violence himself. He was active in Carlist propaganda, e.g. organizing homages to requetés fighting the revolutionaries in Asturias in 1934, though it is not clear whether he engaged in Carlist anti-Republican plots. One source vaguely suggests that Casariego did conspire and another one notes that he was many times detained. Most specific information is that Casariego led some 160 Carlist paramilitary when training warfare near Oviedo, engaged in Sanjurjada and briefly sought refuge in Portugal.