She was also the publisher and editor of the magazine Luz y sombra (Light and Shadows), dedicated to promote culture among and understanding of blind people.

As a radio journalist, she made a name for herself in Radio "Nuevo Mundo", where her daily magazine program María de la Cruz habla (María de la Cruz Speaks Out) was a great success.

These actions were the culmination of a long struggle that began in 1913 and ended in 1949, when President Gabriel González Videla signed the law that granted the right to vote in all elections to women in Chile.

In 1948, de la Cruz ran for a senate seat, but even though she had the support of Carlos Ibáñez del Campo, she lost the election.

After he won the presidency, he offered her a position in his cabinet as Minister of Education, but she refused, nominating instead María Teresa del Canto from her own party.

She also obtained the support of the Partido Democrático de Chile, the Movimiento Nacional Independiente, the Organización de Mujeres Independientes, the Movimiento Nacional Ibañista, and her own Partido Femenino, being elected senator on January 4, 1953, the first woman ever to reach the Chilean senate.