It is fairly obvious that this Loughner fellow has a mental illness. His attack has nothing to do with politics and everything to do with the fact that our laws make involuntary treatment for the mentally ill nearly impossible.
It is important to emphasize that as a result of this attack, we have lost the very conservative Republican anti-immigration chief judge of the District of Arizona, John Roll, opening up the opportunity for Obama to replace him with a pro-immigration Hispanic. No politically motivated assassin in his (otherwise) right mind who is "connected" with AmRen would ever have done such a counter-productive thing.
From a political perspective, Loughner's targeting was, in a word, insane.