It was probably too much to hope that the chattering classes would keep their desire to spin the tragedy in Boston in check for long. Filling the air and the Web with copy in the absence of any real information about who is responsible for the bombing at the Boston Marathon places a real burden on those who comment about such things to avoid sending the discussion off the deep end. Though there are some exceptions, such as MSNBC’s Chris Matthews (who couldn’t wait to speculate about the bombs being planted by radical right-wingers), it is a test that many are still managing to pass. With alerts about letters with toxins arriving at the Senate and the White House and worries growing about any possible connections to the terror attack, the need for the media to behave responsibly is greater than ever.

As I wrote yesterday, the eagerness to put Boston in the service of some political agenda is palpable. Those who are going off the tracks by engaging in pointless and inflammatory speculation unconnected with the facts don’t merit the attention that a refutation would give them. But in the absence of any way to start blaming the event on some group, some are beginning the process of spinning the possible scenarios already. An example of that came in an article published last night in Salon by David Sirota, in which he expresses the hope that “the Boston Marathon bomber is a white American.” The conceit of this inflammatory piece is that a white American terrorist would be treated as a “lone wolf” whose actions would have no implications on policy or society while a Muslim bomber would be thought of as an existential threat to the country.

The point of this seems to be to claim that an Islamist bomber would set off another backlash against Muslim-Americans such as the one that is alleged to have occurred after 9/11. But Sirota is wrong both about that mythical backlash and about the way white bombers such as Timothy McVeigh are interpreted.

The reason why 9/11 was treated as an existential threat to America is that it was. The al-Qaeda campaign against the West, which included previous deadly attacks on the World Trade Center, U.S. embassies and naval ships, was part of a war that most Americans didn’t notice until 3,000 of their fellow citizens were slaughtered on U.S. soil.

But contrary to Sirota, this didn’t lead to a backlash of persecution against Muslims. From President Bush on down, the U.S. government went out of its way to combat prejudice and, unlike what has been the case in virtually every other war that was forced on America, negative images of Arabs and Muslims in popular culture were virtually unknown in the years that followed. Far from jumping on Muslims, the universal impulse after every homegrown Islamist act of terror, such as the mass shooting at Fort Hood, was to downplay the source of the crime and to pretend that it was unconnected to a particular interpretation of Islam.

Sirota is also wrong about his “lone wolf” thesis. The Oklahoma City bombing was not treated as the act of an individual but was widely imputed to conservatives in general, with Rush Limbaugh being unfairly smeared as somehow inspiring violent extremists in a transparent attempt by liberals to exploit that tragedy to undermine their opponents.

The point here is that we can expect, as Limbaugh noted yesterday, most Americans to be extremely reluctant to draw any conclusions about Muslims even if the Boston bombing or the letters are traced to Islamists. But it is far from clear that the same scrupulous reluctance to cast blame will be applied if the bomber is a right-winger. If Boston is traced to some militia crackpot, expect the liberal media to explode with accusations about the Tea Party.

The lesson here is that this is a time when pundits need to keep their powder dry and cease imputing blame for events when we still know nothing about the identity of the culprits. The desire to use Boston to pile on political enemies is almost irresistible for some people. But it should be resisted.