Now consider the so-called logic right-wingers are using here. They insist, in spite of the facts, that Loughner was a "liberal". Then why would he kill liberals. It wasn't liberals who hated Giffords. It was right-wingers. Sarah Palin was the one who put the graphic of gun crosshairs on Giffords specifically, on her website. It was Giffords opponents who put Giffords image on paper gun targets and invited republican supporters to come out to the gun range and shoot at those targets. It was republicans who said, "if ballots don't work, bullets will". If Loughner was a liberal then he shouldn't have been sympathetic to all of this. What about being a "liberal" should have motivated Loughner to want to assassinate one of the few liberal politicians in his state when there were plenty of right-wing extremists throughout Arizona? Indeed it would be hard to find a few other liberals in the heavily republican enclave of Arizona.
So how do republicans conclude that he was a "liberal" and therefore falsely reason that liberalism is to blame for his actions? They say that he read Mein Kampf and The Communist Manifesto. Of course, most educated people would have trouble understanding why right-wingers think that that the ultra-rightwing writings of Adolf Hitler would be "left-wing", but you have to understand that in the semi-literate world of republicanism, they consider Hitler a "socialist", despite the fact that Hitler was at war with communists, outlawed trade unions and despised socialists. As far as reading the Communist Manifesto, reading it does not make you a liberal. Marx and Engels say, in the Manifesto, that they borrowed basic principles of Communism from the Christian bible. From each according to his abilities to each according to his needs comes from the New Testament book of Acts., for example. Christianity, in its original form, was the socialism that right-wingers hate so much.
Ah, but they claim Loughner was an atheist. As some honest right-wingers have admitted, you are not absolutely required to be a fundamentalist christian to be a republican. There are republicans who are atheists. As I have pointed out there are also right-wing Libertarians, who tend to be more religiously skeptical and favor things like marijuana use. However, for this point to really matter we have to believe that there was anything about atheism that would make Loughner do what he did. An atheist who did not believe that he gets forgiven and admitted to eternal Candyland for saying "I wuv u Jebus" one second before death, would be unlikely to throw away his one and only life like this. Atheists might not believe that god is watching them, but they certainly believe that other people are watching them, and, given that there is no conceivable way that he could have gotten away with this crime and not been subject to either the death penalty or lengthy prison, he was not acting as a atheist.
Right wingers have tried to compare this guy to the Columbine kids, but they actually killed themselves. That might be more consistent with nihilism. Instead, this guy was indiscriminate in his choice of targets.
If Loughner was influenced by anything he was influenced mainly by right-wing ideologies like fascism and libertarianism, which caused him to lash out primarily at liberals. It is clear that his mind was not functioning well to begin with, so it is likely that he would have been highly susceptible to the not-so0-subtle assassination rhetoric that rightwingers have used almost constantly, when they call for armed insurrection against their own countrymen and "2nd amendment remedies" when they lose at the ballot box, as they lost to Giffords.