Its valiant attempt to maintain that tradition of opposition under Castro included being the only newspaper that published the letters denouncing the Castro regime written by Revolutionary Commander Huber Matos from prison after his October 1959 arrest for “counter-revolutionary treason”. 1953, the Diario had a circulation of 28,000 weekdays and 35,000 on Sundays, with 36 to 48 pages, selling for five cents.
The Diario's commitment to its tradition of opposing Castro's regime was evident in its decision to publish letters from a prominent dissident, Huber Matos, while he was in prison. This move showcased its significant readership and influence.