What -- other than a blind bias against George Bush rooted in animus or ideology, or an obduracy bred of arrogance and hubris -- can explain Rather's near-suicidal behavior since his "60 Minutes" segment aired over a week ago.

In that piece, Rather revealed four newly discovered memos from the "personal file" of Lt. Col. Jerry B. Killian, George W. Bush's squadron commander in the National Guard. The memos seemed irrefutable proof that Killian thought Bush a shirker whose defiance of orders was being protected by higher-ups like Col. "Buck" Stoudt.

Rather thought he had a story that could bring down a president. Instead, he has ravaged what remains of the reputation of CBS News and made of himself a cartoon caricature of liberal bias. His stonewalling defense of his Guard story will be studied in journalism schools alongside the frauds perpetrated by Jayson Blair and Janet Cooke.

How could Rather have been so stubborn and blind?

At least two experts consulted by CBS warned against going with the Guard story, saying there were "problems" with the memos. Within hours of the airing of the Rather piece, the web had exploded with bloggers saying the Times New Roman font and "superscript" letters "th" in "111th squadron" appeared to have come from a word processor.

By Thursday night, the story of the forged memos was all over the country. Killian's widow and son declared them fakes. Ben Barnes, who told Rather he used his influence to get Bush into the Guard, was being called a liar by his own daughter.

But the smoke alarms at CBS were not working. Friday, a defiant Rather went on air to denounce his critics as partisans and assert that CBS stood by its story.

Over the weekend, the Dallas Morning News reported that Stoudt had been out of the Guard for 18 months when he was supposed to be pressuring Killian.

Rather's hole card, the testimony of Gen. Bobby Hodges, then head of the Guard, that the memos were consistent with what Killian believed, turned out to be a deuce. Hodges claims that he was misled by CBS into thinking the Killian memos were handwritten.

Shown copies, he dismissed them as computer-generated frauds.

Yet on Monday, Rather, his memos a national joke, his experts and witnesses defecting and recanting, went on air to assert once again the memos were authentic and the president must address the Guard issues. "With respect, answer the questions," Rather thundered at Bush. "The longer we go without a denial of such things -- this story is true."

This was ludicrous. It is the prosecution that must prove a man guilty, not the accused who must prove himself innocent.

Rather's conduct remains inexplicable. Why would he risk his career on the authenticity of 30-year-old memos that CBS' own experts questioned and he apparently got from an inveterate Bush-hater who was demanding anonymity for his accusations?

Of what is CBS now palpably guilty? Certainly of stupidity and gullibility of Olympian proportions. Certainly of an obduracy at odds with any reportorial temperament. Certainly of a blind bias toward the president. Can anyone believe CBS would have clung this long to so patently falsified an attack on John Kerry?

Worse, CBS appears to have been complicit in a criminal conspiracy to use forged U.S. government documents to bring down a president. The man who passes counterfeit money he knows or suspects to be counterfeit is guilty of a felony. And CBS must have suspected it was using counterfeit documents to damage President Bush.

CBS has to take Rather off the air for the duration of this campaign if it is to even begin to restore its reputation and credibility. For where President Bush is concerned, Dan Rather has no credibility left.

An investigation must be conducted into who tried to affect an election and bring down a president using forgeries of federal documents. And Rather and the CBS executives and producers must testify against the hatchers of this rotten plot to which they were an indispensable party, or they, too, must stand trial as accomplices in the scheme.

Dan Rather likely saw himself striding to the podium of the Radio and TV Correspondents' Dinner to accept the profession's highest award for investigative journalism. Now he will be the principal object of mockery and ridicule from that same podium, should he dare to show up.

In a way, this is a tragedy. A flaw in a man's character, magnified by his position of preeminence, brings about his downfall and ruin. In Rather's case, it was pride and a blind hatred of the right that led him to commit a journalistic atrocity that will end up killing not the president's re-election, but his own reputation and career.