Old friend Big Daddy speculates:
From what I can tell, Laughner isn’t a right-winger or a left-winger, and there’s not much coherent about his motivations. He appears to want to create a new currency, a new religion, and thinks that the government is controlling us through grammar. In other words, I don’t think he was after any congress person in particular, not Giffords for her politics specifically. She was simply the nearest at hand.
Given that police are seeking a (EDIT) possible accomplice, we in fact know absolutely nothing about the motivation for the attack. If there is an accomplice, we don’t know if the accomplice planned the shootings that Loughner carried out. We don’t know what the accomplice’s political motivations might have been. We don’t know if there is some larger group involved with the planning, be it a fringe group of PETA or the Tea Party Express.
I’m not saying that any of that is likely, just that, given that police are seeking an accomplice, it’s much too early to say that Gifford was not specifically targeted or that the motivations here were neither left-wing nor right-wing.
People who want to be seen as nonpartisan are always anxious to prove their centrist bona fides by saying “both sides do it” or “neither side did it”. Sully-friendly centrism comes with its own set of biases just as much as partisanship does.