There were really funny characteristics about this guy [Richard Nixon], chief of which would be that he seemed to devote about 85 percent of his waking energy to suppressing any sign of his emotional response to anything that was going on around him, and the other 15 percent blurting out those authentic responses in the silliest and most inopportune ways. And he had these smiles that would come at the most inappropriate times - just flashes that there was an inner life screaming to get out.
Harry ShearerIn the year and a half I was on SNL, I never saw anybody ad lib anything. For a very good reason - the director cut according to the script. So, if you ad libbed, you'd be off mike and off camera.
Harry Shearer