WASHINGTON -- It was bad enough when Howard Dean, interviewed on National Public Radio Dec. 1, spread a conspiracy theory that George W. Bush ignored Saudi Arabian warnings of the 9/11 terrorist attacks. It was worse Dec. 7 on "Fox News Sunday," when the Democratic presidential front-runner neither apologized nor repudiated himself for passing along this urban legend.

None of Dean's frantic opponents for the nomination immediately took him to task, not wanting to defend the hated Republican president. A week later, however, they contemplated whether the doctor posed too easy a general election target for President Bush. Al Gore's surprise endorsement boosts Dean among Democrats but surely does not make him more electable.

A half-hour after Dean alarmed party regulars over television Sunday, Sen. Hillary Rodham Clinton on NBC titillated worried Democrats by hesitating at closing the door for 2004. Although her prospects of being nominated for president remain minimal, normally sober Democrats are looking toward Mrs. Clinton in 2004 because of apprehension about what Dean could do to the party.

Unlike George McGovern in 1972, Dean's core problem is not ideological. It is loose lips: fabricating the story of a patient impregnated by her father, seeking support from pickup truck drivers with Confederate flags, and seemingly exulting in his draft deferment for a bad back. Nothing so worries old-style Democratic politicians, however, as proclaiming the apocryphal warning from Saudi Arabia.

In his Dec. 1 interview on NPR's "The Diane Rehm Show," Dean was asked about allegations that President Bush is suppressing information that he was warned about the 9/11 terrorist attacks. "The most interesting theory that I have heard so far . . . ," Dean responded, "is that he was warned ahead of time by the Saudis." This received scant media attention (except for Washington Post columnist Charles Krauthammer), but Democratic politicians shuddered.

Dean was given a chance to back off six days later by Chris Wallace, debuting as "Fox News Sunday's" moderator. "I don't believe that," the candidate said, then added: "But we don't know, and it'd be a nice thing to know." He concluded: "Because the president won't give information to the Kean Commission, we really don't know what the explanation is." After playing to Bush-haters who listen to National Public Radio, Dean repeated the same canard to Fox's Sunday morning mainstream viewers.

None of Dean's opponents raised the issue during Tuesday night's debate in Durham, N.H., but moderator Scott Spradling of WMUR TV did. Dean still defended publicizing what he now called a "crazy" theory.

Where did Dean pick it up? A Dean spokesman told this column it was "out there." A rival Democratic candidate's campaign suspected it came from "some blog." The Russian newspaper Pravda published reports that Jordan's and Morocco's intelligence -- not Saudi Arabia's -- gave the CIA advance knowledge. The World Socialists circulated a story that the Saudi royal family knew of the attack in advance. Somehow, the urban legend penetrated Dean's mind.

"It's McCarthyism in reverse," one 35-year Democratic political veteran told me. "Dean doesn't understand that he's accusing Bush of something worse than an impeachable offense. It's treason." He and several other Democrats that I contacted all expressed the fear that Bush's political operatives will shred an opposing presidential candidate that undisciplined.

As worries about Dean's nomination rise inside the Democratic establishment, hopes of stopping him diminish -- particularly after the Gore endorsement. To slow Dean even temporarily, Rep. Dick Gephardt must stop him in the Iowa caucuses Jan. 19. That's why these worried Democrats were stirred by Hillary Clinton Sunday on "Meet the Press."

After an impressive performance answering Tim Russert's policy questions, the former first lady would not flatly promise to turn down a presidential draft. "The nomination -- it's not going to be offered to me," she insisted. "But if it did happen?" asked Russert. "You know, I have, I am -- ," she stammered. "I think the door is opening a bit, Senator," Russert concluded. "Oh, no, it's not," Clinton shot back. Finally, when pressed to say she would "never" accept the 2004 nomination, she said, "I am not accepting the nomination."

That was ambivalent enough to intrigue Democratic worriers. It's a slender reed, but still reason for them to think that Hillary Clinton might be there if Howard Dean self-immolates by next summer. They are thinking such thoughts because their prospective nominee is spinning wild conspiracy theories.