Another side of this (the attempted assassination of Gabrielle Giffords - 6 killed, 13 wounded), is that the perpetrator was mentally ill. Some people would like to assume that that means it was a random act - as if the young man might have killed anyone. The fact is that he had singled out Gabrielle Giffords in particular. He shot her in the head (but she lived) and then he shot off many rounds with his automatic ammo cartridge. So there was some political connection. Also - she was concerned about the hate and threats coming from the Tea Party group - so I think that it is more than likely that perpetrator picked up on that. He also ranted about the Constitution, currency and other things that Tea Party people have also ranted about.
But beyond that - mental illness can also be part of a culture. For one thing, the way a culture is, can exacerbate stress. How difficult it can be to fit in, to start out in life. Expectations. Bullying has often show up to be a problem with the perpetrators of massacres by young people, though it hasn't been mentioned here that I know of. Jared Loughner may well have been Schizophrenic, but much of the Tea Party stuff exudes paranoia - so he may have naturally picked up on that. Being mentally ill does not make someone violent - but if someone listened to enough stuff that encouraged violence, as Tea Party people have been doing, it's not so hard to see that having an effect.
And the other thing is that it's the right-wing (and esp. Tea Partiers) that is against providing mental health services, just as they are against making health care accessible. It's all part of the same concept that those on the left support - the government providing services for those who need them. The delusion on the right is that people should take care of themselves, as if everyone is capable of that. So in their world, apparently even Schizophrenic people would all hold jobs. Really - I don't know what they expect. That their families will care for them? That churches will? They certainly don't want the government to - it's not in the constitution. Or maybe it is - but if it was - they would deny it. The only thing they want to government to do is provide the military and perhaps couple of other things. Maybe states could provide roads (but even those have been sold off).
My fear is that most of the people of the Right wing/Tea Party are mentally ill (and are at least delusional and somewhat paranoid) - and that could amount to third?half? of the country. So many people persuaded by nonsense - persuaded against what is in the interests of the vast majority of people in this country. There are too many people who will not accept reality and there are too many people who are all too happy to stir up anger at the government - as if we would be better off being run by a corporation (for the profit of those in power).