He got fired for shooting off his mouth. Sanchez basically insulted his bosses... not only did he imply that Jews were elites within his own news network but he stated that he was held back because he was Cuban-American. That sounds like a employee with a chip on his shoulder towards his employers.
I really like Rick Sanchez as a person because he is honestly passionate and honest but he was too impulsive to anchor a news broadcast. He shot off his mouth too many times... the thing is that I doubt he even believed what he said. He just let his temper run his mouth. You can't have people with that impulsive nature representing a agency like CNN.