Jared Loughner killed a representative, because he was apolitical. That makes no sense. If he was apolitical he would have gone to kill someone else, maybe the girlfriend who broke up with him.
When a person goes to kill another, they are fully focused on what enrages them. Let's take the guys who were fired from work. They went back to the place of work and began opening fire. We know why they were unhinged because of what they did and where they did it.
Watching Zeitgeist the movie, taking Tai Chi classes, or yoga classes did not set this guy off. Now I did note that one of the girlfriends mentioned that when she broke up with him, he became slowly a different person. I will also take note that there are some politically motivated individuals who enjoy bashing women, feminism, etc. These are the same individuals who have shifted more and more to the conservative right wing political spectrum. Also take note that he shot a female politician. If you want to psycho-analyze this guy, I would say take the ramblings of the "conservative" movement against women in general.
The news media is afraid to point the finger at the conservative movement in general. Despite the fact that many of them have committed acts of terror against abortion clinics, the Oklahoma Murray Building, and the Waco fiasco. There are also militias running around in the woods with their guns hoping to take on the federal government at any moment. Like someone said before me, the guns did not work too well against the Feds' Bradley tanks in Waco.