So I'm watching the entire series, straight through. In the third episode of Season 2, when Jack and Locke and Kate encounter Desmond in the Hatch for the first time, Jack's reaction is almost violently reactive. He refuses to accept anything that is told him, not the least the order to put down his gun or Locke dies.
Jack's obstinate refusal to accept the oddities of the island - his insistence on keeping everything on the level of the mundane, despite multiple evidences that there is something far more happening - is in many ways the predicament so many of us moderns face. We are put in situations that defy easy explanation. We face events that seem to defy any rational understanding, or understanding based on our previous experience. Jack's violence, his insistence that reality conform to his own blinkered, limited understanding of reality is too often the reaction we see in people who cannot, will not seek to understand what is really happening. They refuse to accept what should be quite clear and plain because it falls outside their accepted canons of understanding.
Jack, in other words, is a Tea Partier. He is also, in these episodes (and in many others) quite an asshole. Were I on the island, I would quite quickly tire of him.