What we have here is a clear case of a self-fulfilling prophecy. The national and local media knew exactly what they were doing. They hyped to a pool of 300 million Americans over and over again that a deranged tea partier is going to gun politicians down. Then, a highly suggestible paranoid schizophrenic acts on the hype and the media instantly blames the tea party.
If they continue to hype this, it will cause more deranged copycats to act.