OK, this is genuinely bad news:

Rep. Raul Grijalva says that the FBI has confirmed the white powder in an envelope delivered to his office is a toxic substance.

It has not been confirmed exactly what substance was mailed to Grijalva's offices, located at the 800 block of East 22nd Street.

A staff member called Tucson Police earlier today after finding an envelope containing the suspicious white powder. The offices were locked down by Tucson Police, and the FBI arrived to assist in the investigation.

Let's be real clear: It's already considered an act of terrorism to send someone a letter with powder in it, as many right-wing fanatics have done in the past decade and more -- specifically, it's a kind of piggybacking, as in the case of that deranged Malkin/Ingraham/Coulter fan, Chad Castagana:

What Castagana's case demonstrates, clearly, is the way terrorism functions. Initial attacks always inspire subsequent rounds of echo attacks that intentionally feed off the terror created by the earlier rounds. It's called "piggybacking," and it has been an explicit strategy of the extremist right for two decades and longer.

The shape of Castagana's threats -- sending white powder in an envelope and including threats suggesting the powder is anthrax -- has been around for awhile. He almost certainly got the idea from its earlier perpetrators, most notably Clayton Waagner, who terrorized hundreds of abortion clinics with similar hoaxes.

Waagner's threats, in turn, piggybacked off the very real anthrax terrorist who killed five people, sickened dozens more, and scared the bejeesus out of the media for a couple of weeks, until they figured out that it most likely was a domestic terror attack.

And the anthrax terrorist, likewise, clearly piggybacked off of 9/11: the attacks occurred two weeks later, and the rampant speculation in the media for quite awhile was that this was another Al Qaeda attack, or perhaps one from Iraq.

Terrorists of all stripes -- foreign and domestic, Islamist and white nationalist, competent and incompetent -- have a symbiotic relationship with each other: one attack creates an "echo" that often has its own idiosyncratic purpose, but simultaneously enhances the intent of the original terrorist attack. The one thing all terrorists have in common, after all, is a general intent: to destabilize public confidence in the government and thus topple it. In the case of far-right domestic terrorists, they hope to present themselves as an authoritarian alternative to a system unable to keep its citizens secure.

What distinguishes those cases from this is that the powder they sent was benign, and the actual threat thus considerably diminished.

Now someone has sent genuine hazardous material that could have sickened Grijalva's staff.

Rep. Grijalva has already been the subject of death threats. Now it has escalated well beyond that.

This is some serious terrorism. It needs to be treated that way. Let's not let the media sweep this one under the carpet.

Rep. Grijalva is a friend of ours from many visits. Be sure and show him some support if you can.