This should be a major news story -- deserving of signifcant coverage on cable TV and on leading mainstream media news sites:

SPOKANE, Wash. — A backpack found along the route of the Martin Luther King Jr. march in Spokane contained a bomb “capable of inflicting multiple casualties,” the FBI said Tuesday, describing the case as “domestic terrorism.”

The FBI said the Swiss Army-brand backpack was found about 9:25 a.m. PST on Monday on a bench at the northeast corner of North Washington Street and West Main Avenue in downtown Spokane.

In an interview on msnbc cable's “The Rachel Maddow Show,” Spokesman-Review reporter Thomas Clouse said confidential sources told him that the device was equipped with a remote control detonator and contained shrapnel.

The fantasically good news here is that a major tragedy was averted -- in large part because of alert Spokane citizens who spotted the backpack, thought it suspicious, and called the police, just as authorities have asked the public to do ever since 9/11. The bad news, of course, is that someone out there wanted to cause a major tragedy -- on Martin Luther King Day, no less -- and that person, or persons, is still at large.

An explosion and the potential for multiple murders that a shrapnel bomb could have caused to those celebrating Dr. King's legacy would have been a staggering blow to a nation that is still reeling and feeling the aftershocks of the first assassination attempt against a member of Congress in nearly 33 years. Even though the bomb didn't explode, the episode raises deeply troubling new questions about the extent of violent politically fueled anger in America in 2011, and why it seems that liberal targets like Democratic Rep. Gabrielle Giffords and now King Day marchers are the ones in the crosshairs, to use the controversial word of the day.

In other words, it's what Joe Biden might call a BFD. But you wouldn't know that if, for example, you visited the two websites that -- in my own 30 years of experience as a journalist, for better or worse -- do more than any other to set the agenda on national coverage in newsrooms across the country.

One of those (note I said “for better or worse”) is The Drudge Report, which ultimate Beltway insider Mark Halperin has said "rules our world." In the 16 or so hours since the FBI went public with the “domestic terrorism” angle, Matt Drudge has spotlighted articles about things like a man arrested for taking photos at Miami airport, a blogger who may lose his firearms permit for a post related to the Tucson massacre, and laser incidents against airplanes -- but nothing about the thwarted Spokane bombing.

OK, so that's Matt Drudge -- but the silence of the leading mainstream news website -- that of the New York Times -- is a little harder to explain. I've checked their home page at least a half-dozen times since last night, and I have yet to see a featured story on the FBI investigating “domestic terrorism” in Washington State. The lack of Times coverage may explain while for the most part, the coverage of this story on cable TV -- the people who routinely hyped run of the mill car chases and blown-tire airplane landings -- has been very minimal. I say for the most part because there have been a couple of exceptions. “The Rachel Maddow Show” on MSNBC featured the Spokane story as major breaking news at the top of its broadcast last night, and for a time it was the lead story on the Huffington Post. Major news outlets -- but with a liberal orientation.

Which is why I can't help but wonder if there's a backstory here related to the past weeks coverage of the assassination attempt on Rep. Giffords, and the right-wing critique of some of that coverage. As you surely recall, the fact that a Democratic congresswoman was targeted in a state that has been a bastion of the Tea Party Movement and unrest over issues like illegal immigration provoked a number of articles about political rhetoric on the right -- including the fact that Giffords had been mapped with crosshairs in the now famous political mailing by Sarah Palin's PAC.

When it emerged that alleged gunman Jared Lee Loughner was an almost certainly mentally ill 22-year-old who seemed to follow some bizarre conspiracy theories but not the political rhetoric of Palin or the Tea Party, there was massive pushback from conservatives who accused the mainstream media of jumping to unfair conclusions. Most famously, Palin herself emerged to call this a “blood libel.” The former GOP veep nominee was savaged for using that charged term, but you have to wonder now if the pushback from Palin is actually a case of “mission accomplished.”

That's because with this new episode in Spokane, not only have the pillars of the mainstream media not raced to any conclusions, but they seem to be in a competition as to who can most ignore the story altogether. But there's no need to jump to unwarranted conclusions here; the actual facts have been laid out by the nation's preeminent law enforcement agency, the FBI -- that we are dealing with a case of “domestic terrorism,” that the sophisticated device along the King Day parade route was capable of causing mass casualties, and the target was American citizens celebrating an icon of the progressive movement, Dr. King.

Maybe the implications are just a little too frightening for the mainstream media to want to deal with. But this episode seems to clarify what some of us have been reporting and writing about for the last two years, that there is an escalating tide of political violence in this country, and the majority of perpetrators or incidents involve the targets of eliminationist rhetoric from the right wing. This is a major issue for America -- on a par, in my opinion, with U.S.-China relations or the future of health care reform -- and the media is dropping the ball here, big-time. It's not too late to pick it up.