Timothy DalrympleThe swiftness with which Jared Lee Loughner's mass murder was blamed on the Tea Party Right was deeply revealing.

Conservatives are often accused of possessing a black-and-white worldview that is impervious to inconvenient facts and thus unsusceptible to revision. The difference between the Left and Right, however, is not that one does and one does not possess a sophisticated worldview, but that each finds nuance and simplicity in different places.

In this case, the self-appointed guardians of nuance on the Left are committing the intellectual and political sins of which they so frequently accuse the Right.

As soon as I heard that a Democratic congresswoman had been shot in Arizona, I knew the accusations were coming. They came so quickly not because the liberals who made those accusations carefully examined the evidence and were reluctantly convinced that their fellow Americans across the aisle bore a share of the blame. The committed empiricists of the "reality-based community" issued their accusations eagerly and well before the facts were in evidence.

Paul Krugman, for instance, wrote on Saturday that "we don't have proof yet that this was political." Did he then caution against leaping to conclusions, as so many journalists and politicians did when Major Nidal Hassan screamed "Allahu Akbar" and opened fire on American soldiers at Fort Hood? Far from it. "Odds are" that it was political, Krugman wrote, and then proceeded to treat the matter as settled, blaming "opposition to health reform" and the fact that Representative Giffords is "a Democrat who survived what was otherwise a GOP sweep in Arizona." He ominously quoted Giffords' father's statement that "the whole Tea Party" was her enemy.

Bear in mind: the shooting had just happened two hours prior to Krugman's blog post, and no evidence had yet emerged that Loughner was opposed to health care reform or belonged to the Tea Party movement. And after Krugman had finished accusing the leaders of that movement, and the familiar villains of talk radio and television, of complicity in the assassination of a United States representative and the murder of innocent bystanders, he had the cluelessness to condemn the "climate of hate" in American politics today.

The emergence of facts that challenge his interpretation has done nothing to change Krugman's mind. It was originally reported that Loughner's online ravings were "anti-government." Yet it turns out that Loughner condemned the government not for deficit spending or for creating inefficient bureaucracy, but for conducting mind control. No evidence has emerged that Loughner has ever once listened to Rush Limbaugh, or attended a Tea Party rally, or fixated on Sarah Palin's "cross-hairs" graphic. In fact, classmates describe him as "left wing," "quite liberal," and a "political radical." He appears to have become obsessed with Giffords after they met in 2007—before Sarah Palin arrived on the scene, and well before the Obamacare and the Tea Party movement. How many Tea Partiers burn American flags on camera or praise Karl Marx and Friedrich Engels' Communist Manifesto?