It is a toss-up which is scarier: the clips in which John McCain allows his supporters to shout “Terrorist!” and “Kill him!” at Barack Obama or the clips in which he tries to calm them. In the former, you see something pretty close to a lynch mob; in the latter, you realise that the eliminationist tropes, while fanned by the McCain camp, now have a life of their own.

“I don’t trust Obama,” a woman says in the second clip. “I have read about him. He’s an Arab.”

“No, ma’am,” replies McCain. “He’s a decent, family man, [a] citizen that I just happen to have disagreements with on fundamental issues and that’s what this campaign is all about.”

Parenthetically, imagine if the woman had said she didn’t trust Obama because he was a Jew — and McCain had reassured her that, no, he was a decent guy, without a Jewish bone in his body.

But let’s leave aside the internalized anti-Arab racism encapsulated in that little exchange. The fact that the Obama-Muslim fantasy could be articulated directly to a presidential candidate — and then cheered by much of the crowd — indicates something about the hallucinatory mood prevailing amongst the American far-right.

Yes, it’s been deliberately fostered by Karl Rove’s manifold disciples. Thus state GOP Chairman Jeffrey M. Frederick directed campaign canvassers — in front of a reporter from Time, mind you — to compare Barack Obama and Osama bin Laden.

“Both have friends that bombed the Pentagon,” he said. “That is scary.”

This is not the equivalent of denouncing your opponent as a fool or buffoon. The comparison with bin Laden identifies that Obama is a mass murderer who should be hunted down and killed.

But while the Republicans might flirt with murderous rhetoric, it’s no longer a tap that can be turned on and off. Accusations of terrorism have become a staple of a right-wing blogosphere, currently swirling with insane anti-Obama narratives. Obama studied in a madrassa. Obama forged his birth certificate. Weatherman William Ayers ghosted Obama’s book.

All this stuff has an effect. The first clip comes from a Republican rally in Pennyslvania; it’s not clear where the second comes from but it’s freakin’ frightening.

We now face a perfect storm of far-right derangement. In all probability, it will be a black President that presides over the looming recession, a black president who begins the retreat from Iraq and a black president in charge of the Afghan quagmire. That’s the significance of the new Right-wing talking point about ACORN and voting registration: die-hard wingnuts are already preparing grounds on which to argue that an Obama administration was fraudulently elected and thus has no democratic mandate.

You will remember that the Clinton presidency saw an upsurge in militia activity, with gangs of armed white men across the country muttering about black helicopters and the UN and the coming of ZOG. That was the milieu from which came the Oklahoma bombing. It was a milieu that fostered precisely the mentality that sees the Obama campaign as representing socialism taking over the USA.

But the internet has added a whole new dynamic, since it’s the perfect medium for right-wing demagoguery, providing a mass readership for the kind of prose TS Eliot once described as ‘the braggadocio of the mild-mannered man safely entrenched behind his typewriter’. The indispensable Sadly No! provides some recent samples.

When you read them, bear in mind that a President Obama, while clearly in some physical danger, will have pretty heavy duty bodyguards to protect him. That’s why most of this mounting rage won’t be vented against anyone in high office – it will be ordinary people of colour who take the brunt of it.