It was a cold night in early January when Dana Goldstein, a writer for The American Prospect, was interviewing caucus goers in the auditorium of Des Moines’s Harding Middle School.

She started talking with a supporter of John Edwards. When he said he disliked Obama, Goldstein asked why. Among other things, he mentioned e-mails he’d read claiming that Obama was a Muslim.

“There are so many rumors about his background, and you know, it’s scary,” Goldstein quoted him as saying.

“This is not in my piece, but I remember what I said: ‘I don’t think that those rumors are true,’” Goldstein says. “And I don’t know if I did the right thing or not, but I didn’t feel like I could stay silent.”

“My simple answer—‘I don’t think that’s true’—sort of felt like a way to stay somewhat objective and still cast some doubt on what he said,” says Goldstein. “I guess objective is the wrong word. I’d say somewhat disinterested.”

It’s a scene that has, no doubt, happened thousands of times to reporters covering this campaign: during the course of an interview, a voter alleges that, despite all evidence to the contrary, Barack Obama is a Muslim. (Of course, whether or not he is should be immaterial, but Islamophobia exists, and some voters are weighing false information about Obama’s beliefs.)

“I hear it all the time,” says Wes Allison, a national affairs writer for the St. Petersburg Times. “In New Hampshire, I’ve heard it. In South Carolina I’ve heard it. In Florida I’ve heard it. In Pennsylvania I’ve heard it.”

When this allegation makes it into print, it’s usually followed by a note making clear that the contention is false. But that sort of correction doesn’t always come as quickly, routinely, or easily during the course of the actual interview. And this raises questions about the proper balance between a host of competing interests and ideals: impartiality, setting the record straight, getting the best interview, and being honest with sources.

“I don’t correct,” says Allison. “And honestly, it’s not that I want people to have the wrong impression.

“But my mission’s not to change the minds of the voter, but to report on the texture of what voters are thinking,” says Allison. “Every person I interview represents ten people. And if I didn’t let him finish, I’d never hear what his ten friends from the diner were saying.”

“For me to say he’s not a Muslim, that interrupts the flow… It’s like dropping a two by four in the creek,” says Allison, adding that if the conversation is long, he might work in a correction as a way of probing the origins or strength of the false belief.

That idea of using the truth as a tool to push interview subjects is the main reason that Michael Powell of The New York Times says he tries to correct the record in every interview where the Muslim claim arises, as it did while he was reporting in Pennsylvania over the summer.

“Almost without exception, you’ll get a more interesting answer. The point isn’t to try to get in an argument with people. The point is to draw them out,” says Powell. “I’d love to say it’s out of some sense of high ethics, and maybe it is at some inchoate level, but it’s also out of good journalism, or more interesting journalism, because you’re going to get a more revealing response if you poke and prod people.”

Earlier this month, a version of the falsehood grabbed the news cycle when Gayle Quinell, a seventy-five-year-old McCain volunteer, took the microphone at a town hall forum to tell her candidate that she couldn’t trust Obama because he was “an Arab.”

After the event broke up, reporters found Quinnell, and Adam Aigner-Treworgy of MSNBC asked about how she came to believe that Obama was a Muslim. After several rounds of this, CNN’s Dana Bash chimed in to explain that Obama’s father was Muslim, but that Obama had never been a Muslim, and that he was a Christian. The exchange was uploaded to the internet by TheUptake, a citizen journalism Web site.

“I think it is a fine line when you are talking to someone who doesn’t have all the facts,” said Bash. “I think it’s really, really, important to make the case that it’s not my job, nor was I trying to convince her that Barack Obama is a Christian. What I was trying to do after she had gotten a lot of questions about how she got her information was to see how seared that information was into her head, and to see whether or not she was open to other ideas, and to the idea she might be wrong.”

Bash was adamant that any story she’d produce mentioning the falsehood would include a line explaining that Obama is not, in fact, a Muslim. I asked Bash if she thought there was more of a place for that in a story than in a real-time interview.

“I think it’s both,” she responded. “What do we do? We try to put out correct information as reporters. That’s our job. In part, saying, wait a minute, he’s a Christian, it was trying to inform her. She doesn’t have to wait for my piece on television. She doesn’t have to wait for my live shot. She can hear me there.”

Daniel Malloy is a young reporter at the Pittsburgh Post-Gazette. Earlier this month, he wrote a piece exploring voter opinion in a rural county in southern Pennsylvania. Before he began reporting, he considered how he’d handle it if anyone repeated the Muslim lie to him. He decided that spot corrections were necessary.

“We are journalists and our job is to inform the public,” he says. “When I write this story later, I’m going to say that he’s not a Muslim. So when this person reads this story, is it going to be weird for them to read it in the paper but not have heard it from me? That’s a little bit dishonest, almost. If it’s supposedly our job to educate and inform the public, we should be educating and informing the public verbally as well as in the written word.”

I’ve only had one experience reporting on the campaign where something like this came up. It was during April’s Pennsylvania primary, and I was at a rec-building polling station in a northeast Philadelphia park, interviewing people about where they’d found their information on the candidates.

Hector Rivera, a thirty-seven-year old bricklayer, had clearly spent a lot of time reading about the election, and was proud to tick off his news sources and what he’d learned. But I was a little taken aback when he vaguely mentioned Obama’s father and stepfather, just before claiming that when Obama “was sworn in to the Senate, he did it on the Koran, not the proper Bible.”

I asked Rivera where he had read that.

Human Events,” he said. “Someone e-mailed it to me.”

And then I told him that that he had in fact been sworn in on a Bible, and that what he’d heard was just a rumor.

“It’s a rumor? Then that’s not right for people to say,” said Rivera.

That response was much more surprising to me than his original claim. How could someone who was so up on the election—seconds before, he had referenced Clinton’s dodgy landing-under-sniper-fire anecdote—have seen the Muslim rumor, but not seen information that would have set him straight? And why was he so willing to believe me once I told him he was wrong? And why would it have mattered to him if the Koran statement were true? I wish I’d thought to ask.

In any case, my experience seems to be an exception. The reporters I spoke to said that any real-time corrections to the Muslim rumors almost always have no impact. Interviewees say something to the effect that the rumor—even if they weren’t entirely sure of its veracity—was still enough to trouble them; or they make some factually true, if still Islamophobic, statement, like pointing out his Muslim ancestry.

It’s a depressing thought for a journalist: no matter when you point them out, sometimes the facts don’t matter.

Clint Hendler is the managing editor of Mother Jones, and a former deputy editor of CJR.