This word is used in the following sentence. I can not find any definition in my dictionary. " Ante la embestida del carrerismo algunas familias del régimen adoptaron posturas de semioposición y comenzaron a airear alternativas reformisitas con la esperanza puesta en el posfranquismo."
I guess you are talking about the Spanish Civil war? Your word carrerismo could mean the philosophy or politics of someone name Carrera Have you ever heard the term "Nixonian" point of view, refering to President Nixon philosophy or point of view.So carrerismo could be something like that. Carrerismo can also mean some ones life work as in career.
Carrerismo. In your context it seems to be related with Almirante Carrero Blanco