In 1995, when a right-wing anti-government extremist named Timothy McVeigh detonated a bomb in Oklahoma City, killing 168 people, U.S. President Bill Clinton pointed a finger at the rhetoric of "culture war." Talk radio hosts and their audiences didn't simply disagree with fellow citizens who happened to be on the other side of the political fence, Clinton said. They despised them. They called them "enemies." They used vicious language. They had no sense of fairness and accuracy. They used any evidence they could get their hands on, however tenuous, to concoct wild stories of conspiracies that would "destroy America as we know it." Clinton warned that a Petri dish filled with that stuff will grow some dangerous forms of hate. It all seems so long ago. The political discourse of that era sounds like a Boy Scouts sing-a-long compared to the rage and bile pouring out of the American media today. Talk radio has become a scorched and twisted wasteland where Rush Limbaugh -- the bête noire of the Clinton era -- is a relative moderate. The blogosphere is more varied, but the haters are even more hateful. And television? The virus introduced by Bill O'Reilly when his show debuted in 1996 on Fox News has mutated and multiplied, growing steadily more virulent. What will follow the paranoid, lachrymose, megalomania of Glenn Beck is anyone's guess, but it's a safe bet that when Bill Clinton watches Beck sketch his latest insane fantasy on the chalkboard he pines for the intellectual refinement of Geraldo Rivera. Not even books are safe from the madness. Find a political book on the New York Times bestseller list and more often than not it will read like a talk radio transcript. Even the more erudite fare is written by zealots for zealots, with those who disagree grotes-quely caricatured: Conservative Jonah Goldberg links liberals to Nazis in Liberal Fascism, so liberal Markos Moulitsas links conservatives to medieval maniacs in American Taliban. Meanwhile, a plug from Glenn Beck can make any book a bestseller and Beck's first suspense novel -- a paranoid tract about evil liberals bent on destroying America, naturally -- tops all lists. What this says about the drift of American political culture is fascinating, and disturbing. But I'd like to think of it on a more fundamental level. Arguably the most important of the many psychological biases identified by researchers is "confirmation bias." It's a simple and powerful concept: Once we believe something, for any reason, good or bad, we will happily and uncritically embrace anything that confirms the belief while harshly scrutinizing -- or simply avoiding -- anything that contradicts it. In a sense, the struggle for human rationality -- to see the world as it is -- is nothing more than the struggle to overcome confirmation bias. In the "culture war" discourse that has overtaken the United States, there is no effort to overcome confirmation bias. Instead, confirmation bias is embraced: The like-minded assemble in tribes, congratulate each other on their superior virtue and wisdom, and energetically collect and share information that confirms they are completely and absolutely right about everything. No effort is made to seek out information which may suggest otherwise -- and if such information is thrust under their noses, they will rationalize like mad in order to dismiss it as utterly worthless. In response to the death-spiral of American discourse, a number of respected fact-checking organizations have been created. One of the first was Spinsanity, co-founded by political scientist Brendan Nyhan. "One of the things that we tried to do at Spinsanity was just to show in excruciating detail how frequently people like Ann Coulter and Michael Moore distorted the facts," he said in a recent NPR interview. Of course the zealots have no use for such efforts. By definition, criticism comes from the enemy. So it's biased. And can be safely ignored. But people like Nyhan know mere facts can't change the minds of zealots. They want to do something different. "At some point, people have to be cast out of polite society," he said. "You have to simply say, that is irresponsible and we're not going to give you our air time, or our print, to make that sort of claim." So far, polite society in the U.S. would prefer to make money from the likes of Glenn Beck than put him on an ice floe. But things are a little different in Canada. There's lots to criticize about our media. Too parochial, timid, wary of giving offence. Too unimaginative and boring. Way too much cronyism. But the virus that has swept the U.S. is scarcely to be found in this country. Canadians should be proud that even the biggest know-nothing loudmouths on Canadian talk radio are models of moderation and sweet reasonableness compared to what's on American airwaves. This is what makes the abrupt resignation of Kory Teneycke so important. As vice-president of media giant Quebecor, Teneycke intended to do more than create what critics called "Fox News North." The hiring of zealots. The inflammatory rhetoric. The conspiracy fantasies. The sheer unreasonableness. Teneycke is infected with the American virus -- and he intended to pass it along to a major Canadian media company. I don't know why he is out. But I do know it's good that he is.