See Slate's complete coverage of the Gabrielle Giffords shooting and arrest of Jared Lee Loughner.
Of course it was political.
In the Fort Hood shootings of November 2009, the right was quick to link Nidal Malik Hasan to terrorism, while the left insisted he was merely deranged. The reactions to the attempted assassination of Rep. Gabrielle Giffords and the murder of six others this weekend offered a mirror image: Many on the left blamed right-wing political extremism, while conservatives insisted that Jared Loughner, the alleged killer, was a lone lunatic, without political motivation.
If a whiff of political opportunism clings to both these sets of reactions, it's because the categories that we use to explain political violence draw bright lines where none really exist. Throughout history, political assassins—even the most clearly unhinged among them—have possessed political motives. That doesn't mean that Tea Party-style rhetoric incited Loughner. But his choice of targets—an officeholder, not a post office or a mall—can't be dismissed as arbitrary. The problem lies in the artificial distinction we routinely draw between political and psychological motives.
Before the rise of liberal democratic norms, when violence was a common and viable way to overthrow political regimes, there was seldom doubt that an attack on an office-holder was political in nature. The insanity defense became plausible with the M'Naghten Case of 1843, in Britain, in which Daniel M'Naghten, trying to kill Prime Minister Robert Peel, instead murdered Peel's secretary. The House of Lords then developed rules for accepting claims of insanity. They allowed the defense in instances where mental disability meant that the accused did not know "the nature and quality of the act he was doing; or, if he did know it, that he did not know he was doing what was wrong."
Over time, these guidelines and the ideas that informed them made their way into American law. They came to shape public discussions about assassinations as well. When John Wilkes Booth, a vehement defender of the Confederacy, murdered Abraham Lincoln, virtually everyone agreed that he acted for political reasons. He was part of ring that also targeted Vice President Andrew Johnson and Secretary of State William Seward. Although historians have debated the precise nature of Booth's motives, few have doubted that he did so to aid or redeem the Confederate cause.
In the late 19th century, however, psychiatry began influencing criminology. The new approach to crime and the law created more opportunities for insanity defenses—in not only the courtroom, but also the court of public opinion. What began to emerge was today's sharp distinction between political assassination (which was deemed "rational" and the expression of an ideology) and derangement (the condition of an isolated individual).
When Charles Guiteau shot James A. Garfield in July 1881, his sanity was a central point of contention. It was obvious that Guiteau targeted Garfield for political reasons. Deeply invested in the outcome of the 1880 presidential election, he grandiosely expected to be recognized for a pro-Garfield pamphlet he had written, even though he had no significant connection to the campaign. That he wasn't appointed minister to Austria or some other office prompted him to beseech the White House and the State Department repeatedly for a position, to no avail—leading eventually to his decision to kill Garfield.