Perspective Shock.

It is simply unimaginable to the left that there are any rational minds opposing them. The majority of news channels, newspapers, entertainment channels, and pretty much anything out of Hollywood comes from the single viewpoint of the left. It is very probable that a person can go throughout their early years and reach their twenties without ever hearing a conservative point of view.

Oh, they might hear the isolated pundit or candidate argue for a responsible stance, but it is unlikely that they would ever really be engaged by a conservative explaining their views. The propensity to scream and name call their ideological opponents makes it even less likely that a non-pundit conservative would stick their neck out and confront a leftist idea that really needs to be challenged.

So, when a leftist encounters a conservative on Fox News, Rush Limbaugh, or any of the other fine conservative talkers and writers, they are shocked to hear a viewpoint that disagrees with what they have been spoon fed for years. They may disagree or simply not understand the new viewpoint to which they are being exposed, but they don't think it's reasonable to disagree with everything they have always heard. So ideas such as the Orwellian Fairness Doctorine or Net Neutrality appeal to them.

The rank and file leftist simply doesn't realize that by shutting down conservative voices they are crushing the diversity that they really need, diversity of thought.