In the most recent case of Hollywood being used to directly influence your thinking on a particular issue, a new commercial shows famous television and movie actors, like Jamie Foxx, Selena Gomez, Chris Rock, and more, saying we all need to talk to our 'leaders' and 'demand a plan' to address gun violence, which I would presume to mean gun control. A parody of this video has been made, showing the hypocrisy of these actors. (video below) If they think guns and gun violence is so bad, why do they play in movies that use so much of it?
Hollywood has been used to push political agendas before, and the use of movies and television programs, by government, to push certain views onto the viewer is NOT secret. There have been several documentaries showing the relationship between the pentagon and Hollywood. Many movies that now include the use of the US Military, in any fashion, need to be first approved by the U.S. Pentagon. Some movies, like Top Gun, starring Tom Cruise, are used as a recruitment method to the military. Here are a couple good documentaries on the subject.
Empire : Hollywood and the war machine: "Empire examines the symbiotic relationship between the movie industry and the military-industrial complex."
Operation Hollywood: How The Pentagon Shapes And Censors The Movies - "Have your favorite movies been censored or meddled with by the Pentagon?"
The website, Hollywood Reporter, ran a story on November 11, 2012, titled "Obama's Hollywood Organizers Reveal Winning Strategy That Helped Tip Election", that covers the re-election of Obama, and how actors, musicians, celebrities, etc., were used in an elaborate strategy to influence your vote.
The propaganda is everywhere, look for it.