WASHINGTON - Here come the goons, right on schedule. The "author," and I use the term loosely, whose vicious lies damaged John Kerry's 2004 presidential campaign has crawled back out from under his rock to spew vicious lies about Barack Obama. Right-wing radio talk-show hosts are dutifully transmitting this concocted venom. This presidential campaign has officially gotten ugly.

The "author" I'm talking about is a man named Jerome Corsi. In a book published last year, "The Late Great USA: The Coming Merger with Mexico and Canada," Corsi claimed that George W. Bush was at the heart of a secret conspiracy to subsume the United States into a post-national, one-worldish North American Union. Corsi's writings on far-right blogs have been even more paranoid and delusional.

He has written that pedophilia, for which he used a more graphic term, "is OK with the Pope as long as it isn't reported by the liberal press." He has referred to Muslims as "ragheads."

Corsi would be known as just another visitor from the outer fringe if he had not been the co-author of "Unfit for Command," the book that slimed Kerry's exemplary record as a Swift boat commander in Vietnam. The allegations in that book were discredited, but not before they had been amplified by the right-wing echo chamber to the point where they raised questions in some voters' minds -- perhaps enough to swing the election.

l l l

IT WAS AN ABOMINABLE TRICK, but quite remarkable. Kerry's opponent, George W. Bush, had avoided Vietnam by taking refuge in the Texas Air National Guard. Kerry was a decorated war hero, yet somehow his valor and sense of duty were turned into a political negative and used against him.

Now Corsi, in what he acknowledges is an attempt "to keep Obama from getting elected," has come out with a book that similarly tries to turn one of Obama's strengths -- his compelling life story -- into a liability.

Corsi's new volume of vitriol, "The Obama Nation," seeks to smear Obama as a "leftist" and add fuel to the false and discredited rumor that he is secretly a radical Muslim, or at least has "extensive connections to Islam." The liberal Web site Media Matters has already demonstrated that the book is riddled with factual errors -- for example, Corsi repeats the charge, thoroughly disproved, that Obama was in church for one of the Rev. Jeremiah Wright's most incendiary sermons. But the point isn't to tell the truth. The point is to repeat the lie and thus give it new life.

Corsi's dirty work is more difficult this time because Obama has already written his life story in the autobiographical "Dreams From My Father." Since he can't reveal anything about Obama's past, Corsi is reduced to reinterpretation -- or, at times, invention.

It sounds like the kind of book that should quickly be consigned to the remainder bin, but -- unsurprisingly -- it is already a best-seller. The Washington Post and other news organizations have noted that this and similar anti-Obama books win the imprimatur of best-seller status by being "pushed by conservative book clubs that buy in bulk to drive up sales."

l l l

THIS TIME, THOUGH, SOMEBODY IS PUSHING BACK: John Kerry, whose political action committee has launched a new Web site, called Truth Fights Back, to "fight against the right-wing smear machine." The site weighs in vigorously on behalf of several Democrats who are being hit with unfair attacks, but its most urgent campaign is "making sure Jerome Corsi doesn't get away with his lies unchallenged."

The Obama campaign faces a classic dilemma. If smear attacks are left unanswered, voters can get the impression that the lies are true. But there's no way to respond without giving the falsehoods wider circulation.

For Obama, this choice seems doubly fraught. Just look at the way John McCain's campaign jumped all over Obama when he predicted -- correctly, it turns out -- that Republicans would try to scare voters by making him seem alien and somehow frightening. His observation about not looking like previous presidents was opportunistically slammed by McCain and his surrogates as playing "the race card."

So far, the Obama campaign's reaction to the Corsi book has been fairly muted -- in part because others, such as Kerry, have stepped up to give a more full-throated response. Kerry knows better than anyone what it feels like to be Swift-boated, and he's determined not to let it happen to anyone else.

(Eugene Robinson is a columnist for The Washington Post. Obama's campaign has issued a rebuttal of Corsi's book on its Fight the Smears Web site.)

Get $150+ in coupons in every Sunday N&O. Click here for convenient home delivery.