It will be interesting to see which version of John McCain shows up to debate Barack Obama tomorrow night at Hofstra University on Long Island.

Will it be the slightly embarrassed candidate who gently rebuked a woman at a rally last week when she said, "I have read about [Obama]" and "he's an Arab"?

Or will the candidate who promised supporters in Arlington, Va., that he was going to "whip [Obama's] you-know-what" in their final debate put in a belated appearance?

After traveling the low road of smears and innuendo last week, John McCain would be wise to leave the many bizarre conspiracy theories that have begun circulating recently about his opponent to the dwindling band of columnists who support him not because he's their first choice to be president, but because he isn't Barack Obama.

If Mr. McCain shows up to debate Mr. Obama and he's not prepared to talk about the economy in a way that doesn't remind us of Al Lewis as Grandpa Munster, then he'd better retreat to one of his 12 homes until Election Day.

It would be a mistake for Mr. McCain to turn to Mr. Obama and say with a straight face: "I hear from reliable sources that Bill Ayers either assisted you in writing your first book or ghost-wrote it. Is that true?

"And while we're at it, did Ayers' wife and your wife collaborate on America-hating activities when they worked at the same law firm in the 1980s? Was your college education paid for with Arab money?"

Given Mr. McCain's wicked sense of humor, he could almost get away with it if he broached the subject with a laugh to indicate that he didn't believe such silliness and that he was simply throwing stuff out to see what stuck.

It would be quite the icebreaker. Mr. Obama could pretend to take the question seriously at first before losing his composure and guffawing loudly while pounding the lectern.

They would then have permission to fall into each other's arms, with John McCain admitting through his laughter and tears that it was "just a shot" and that he didn't seriously believe Mr. Obama attended Harvard on a jihad scholarship from Arabs.

Having the laughter of the audience on his side would be the best of all possible worlds for John McCain after last week's debacle.

Any hint of the bellicosity that dominated recent headlines would simply remind voters how out of touch the McCain campaign is with the interests of ordinary Americans.

Now that the race is in its final stretch, the press has begun to examine some of the more outrageous myths of the campaign season.

Yesterday, The New York Times published a fascinating piece by Jim Rutenberg about Andy Martin, the first man to identify Barack Obama as a Muslim terror agent bent on destroying America from the inside.

According to Mr. Rutenberg's piece, "The Man Behind the Whispers About Obama," Mr. Martin is a Holocaust mocker whose bizarre theories about the Democratic candidate's religious views "have found resonance among some Jewish voters" whose own politics make them susceptible to the theory.

Mr. Rutenberg demonstrates how Obama critic Jerome Corsi, author of "The Obama Nation," based much of his own discredited research on the shaky edifice of Mr. Martin's work.

The article also introduces us to the work of Ted Sampley, a McCain critic who once described the Republican presidential nominee as a "Manchurian candidate" before turning his fire on Mr. Obama.

If you've gotten an e-mail in the last two years "proving" Mr. Obama is a Muslim terrorist, it probably originated from an article written by Mr. Sampley.

Mr. Rutenberg reports that a press release written by Mr. Martin and posted on the Free Republic Web site in August 2004 was the basis of the first cyberspace attack on Mr. Obama's claim to be a Christian.

Mr. Martin got a lot of face time on the Fox News program "Hannity's America" recently, where his allegations received a sympathetic hearing from the show's credulous host.

There is intellectual indebtedness between Mr. Corsi and Mr. Martin that should make both men radioactive to anyone who cares about being associated with anti-Semites and rascals.

The woman John McCain rebuked at the rally last week didn't pop from thin air. People like her had a lot of help being born. It's going to take an awful lot of straight talk to turn it around.