Bill O'Reilly did an interesting thing last night when he reran that footage of Barney Frank castigating that woman carrying an Obama-as-Hitler sign at his town-hall meeting on health care: He completely omitted the fact that the woman who Frank was castigating was in fact a member of the far-right Lyndon Larouche cult.

All O'Reilly could muster was to mention that the woman was "a political activist." But that's like calling a Great White Shark a fish.

No, right-wingers like O'Reilly have been eagerly airbrushing out the existence of right-wing extremists from their worldview for some time now, embodied by their reaction to that DHS bulletin. But it's getting harder and harder to do all the time now.

Because, as we've noted, the far-right extremists are bubbling up everywhere in supposedly mainstream conservative circles these days -- particularly at the tea parties and their associated health-care protests.

Most recently, it turns out that the guys who brought those guns to a health-care forum in Arizona in fact were longtime members of the old Arizona Vipers Militia. These were characters who, prior to their arrests in 1996, had stockpiled close to 2,000 pounds of ammonium nitrate and conducted field training exercises, practiced bomb-making, and trained with illegal automatic weapons.

Now, all the Fox talkers have been in heavy denial about extremists showing up for their tea-party protests, even making a regular joke out of it by asking the protesters they have on their show if they're Klan members and the like.

But it's becoming clearer all the time that, while not everyone at these events is an extremist, the percentages of them keep going up and up. And with them, so does the threat to public safety.