I love the comedy of Carlin, Colbert, Stewart, and Maher, but I doubt that they educate anyone. They're preaching to the choir.

For one thing, people who disagree with them usually don't watch them. Only left-leaning people appreciate humor in political discussion. The right uses anger and moral indignation instead.

For another, when right-wing people do watch these comedians, they interpret what they see completely differently than we do. You see evidence of that all the time in YouTube posts, for example this one: https://www.youtube.com/watch?v=WakNCf4Wno4, which the person posting it somehow concluded could be described as "SE Cupp takes down Michael Moore & Bill Maher on Gun Control."