@spendius,
In so much that we're all a product of our environment, I agree with you, spendi. And I agree that the environment of our day to day bombardment of all things negative has an effect. However, we're talking about a mentally disturbed young man who may or may not have participated in, or been affected by, the world around him.
From all reports to date, it appears that this is a Very Troubled Individual who lived within a very small universe -- that space in his head where cultural and environmental influences may not have penetrated.
I do think the overall climate is anything but healthy to all of us. And, I agree, that there may be some who are less disturbed than Mr Loughner who may be pushed to a "2nd Amendment solution" against someone who has been "targeted" by a dynamic and pretty hate-monger.