“Yeah, I’m starting to have second thoughts,” said Garry Biniecki, the undersheriff of Sanilac County in Michigan, whom the Giuliani campaign recently rolled out as a “Michigan Leader.”

Mr. Biniecki said that his support for the former mayor originally stemmed from Mr. Giuliani’s performance on Sept. 11, but he described himself as “a little gun shy” after all the recent coverage: stories about the indictment of his former Police Chief Bernard Kerik, and then, last week, an unflattering report about the ways in which Mr. Giuliani’s administration accounted for his personal security expenses.

“It doesn’t sit well,” Mr. Biniecki said. “And then you wonder what else there is.”

Mr. Giuliani’s campaign has scrambled to put supporters like Mr. Biniecki at ease, holding multiple conference calls with influential supporters to address their concerns, according to Mr. Giuliani’s chief political adviser, Tony Carbonetti.

Also, they have expended considerable energy trying to stanch the damage at its source, after an initial delay, by attacking the story itself.

The article, published on the Politico Web site, revealed that Mr. Giuliani’s security detail had racked up significant expenses accompanying him on trips to Southampton, where his mistress lived at the time, then filed the expenses through obscure city agencies. The campaign has not had a good day since.

The New York press reacted enthusiastically to the security expenses story, with the Daily News and Newsday running multiple front-page follow-ups. (One News headline: “Doesn’t Add Up! Now Rudy Camp Changes Story Over Tryst Dollar Accounting.”)

Then, on Nov. 30, The New York Times wrote a remarkably unequivocal A1 piece detailing the inaccuracy of the statistics he cites on the campaign trail, and ran another story four days later pointing out that the Bracewell & Giuliani law firm, of which Mr. Giuliani is a partner, lobbied for Ethiopian clients advocating positions contrary to American foreign policy.

It all seems to be taking a toll: A USA Today/Gallup Poll of national Republican and Republican-leaning voters published on Dec. 3 showed Mr. Giuliani slipping nine percentage points in a month to 25 percent.

“You have to be honest, and if you are not honest, it will get the best of you, it really will,” said Rhona Charbonneau, former chair of the New Hampshire Republican State Committee and a supporter of Mr. Giuliani. “And if he did something wrong, he either has to own up to it or make an explanation as to why it happened. Not ducking.”

Ms. Charbonneau added, “If he did these things than he should have owned up to it before even running for president. Personally, I would have looked at everything that I had done, and if there was a problem there I would have made sure it was explained prior to my running for election.”

The campaign is doing its best to suggest that there was never anything to explain.

Mr. Carbonetti told The Observer that the campaign reacted slowly to the Politico story because they didn’t have access to the source materials until after the story was published. He also said that the story’s angle had been misrepresented to him, and says that the first time most national campaign staffers heard about the story was upon its publication.

“They all turned to me and said, ‘What the hell is this?’” he said.

He said that the only people who had known about the story beforehand were himself, the campaign’s communications director Katie Levinson and Sunny Mindel, Mr. Giuliani’s longtime spokeswoman.

Mr. Carbonetti said that Ms. Mindel told him after she spoke to the reporter, but before the story was published, that “it was strictly a budget issue.”

Mr. Carbonetti argued that it took some time to settle on a defense—Mr. Giuliani’s original reaction was that it was a political “hit job”—because he needed time to go through the hundreds of pages of documents. He said the documents ultimately showed that the accounting was filtered through the other city agencies in an effort to expedite the payment of travel expenses to vendors.

He said that the process began well before Mr. Giuliani started seeing Ms. Nathan, was common practice among City Hall workers and was intended to circumvent the New York City Police Department, which was a bureaucratic nightmare.

“I can either give you the explanation and you can accept it, or you can see the black helicopters you want to see,” said Mr. Carbonetti. “If you would have wanted to hide it, you would have put it over at PD.”

So far, the explanation hasn’t stuck. Ray Kelly, New York’s current police commissioner, who also ran the department under former Mayor David Dinkins, has publicly contradicted Mr. Carbonetti’s characterization, saying that during his two stints as the head of the Police Department, “detectives assigned to the mayor’s security detail file all of their expenses through the department and they’re reimbursed through the department.”

And the reporter who broke the story, Ben Smith (who used to be a reporter for this newspaper), responded to Mr. Carbonetti’s assertions about not disclosing the nature of the story by showing The Observer a copy of the e-mail he sent to Ms. Mindel, in which he described the nature of the expenses that he found and explicitly pointed out that the trips to Southampton occurred while Ms. Nathan lived there.

“My main question,” Mr. Smith wrote in the e-mail, “is why these expenses were attributed to obscure agencies, and whether City Hall was trying to hide them.”

Some supporters continue—gamely, it must be said—to express confidence in the direction of the campaign, and in its handling of the recent, brutal news cycles.

“Anyone who has been involved in these campaigns in the past knows that you just go through these rocky things, you have to deal with them, and sometimes you just get stronger from having to deal with them,” said Barry Wynn, the chair of Mr. Giuliani’s South Carolina campaign and the former finance chair of President Bush’s reelection campaign. “Just look at the Clintons, and of course, I was in the Bush campaign, and whether it was the National Guard or this or that or drinking or whatever, you just can’t have good week after good week after good week.”

Dismissing attacks from the “Northeast press,” Mr. Wynn pointed to Mr. Giuliani’s strong poll numbers in South Carolina and said that the bad week was mostly a result of an absence of the issue of terror. >

“That is the key question that galvanizes a whole lot of support,” he said. “When that nerve is hit, people do not worry about divorces; they do not worry about perfection. People worry about the survival of the country.” Other supporters argued that the news would have little effect on voters who supported Mr. Giuliani because they felt he would keep American safe from terrorism.

“Everybody understands it’s election-year politics,” said Barron Thomas, a key fund-raiser for Mr. Giuliani in Arizona. “But people are focused on the big issues, that’s Iran and Iraq. If we start examining microscopic details that are really insignificant, it is really going to derail the big picture.”

The question here, then, is whether these details are truly insignificant.

Asked if New Hampshire voters would hold Mr. Giuliani accountable, Ms. Charbonneau said, “Sometimes they forget, and sometimes they don’t.”

Asked which of those things was going to happen in January, she said, “He’s going to have a problem.”