Serious, do we have to go there ? Did that really affect his acting ?
Yes, and Yes.
It affects the roles they play and how they play them, the messages the movies are trying to deliver (overt or cover), and somehow it affects their ego, making them think other people should listen to what they have to say. Hollywood has been used by both sides of the political aisle since "talkies" were invented. Regarding RR specifically, do you believe that "Brubaker" and "The Last Castle" didn't have the goal of trying to soften prison for inmates?
There's an awful lot of actors/actresses (especially those who achieve stardom, or even a little notoriety as children/adolescents) that are undereducated (dropped out of school), or graduated but with a VERY narrow focus (tutored or the acting equivalent of homeschooling) of only what they needed to have to graduate.
It'd be interesting to see one of the talk-show hosts "guy/gal on the street" reporters who goes out and asks what should be easy "general knowledge" questions of the general public, do something like that at a Hollywood "Red Carpet Event". The baseline ignorance of the entire group may astound a few folks.