This kind of behavior creates a tricky problem for the press. How should media companies deal with Trump and his falsehoods? If he were just a joke candidate without a hope of ever being the Republican nominee, it would be easy enough to ignore him. But he appears to stand a better than even chance of getting the nomination — he has been leading in the polls for months.

If media outlets attack Trump’s lying directly, they run the risk of being accused of bias by his supporters and Republicans in general. In fact, that kind of reaction is already occurring in response to a New York Times editorial that accused the billionaire businessman of playing fast and loose with the truth on a number of issues, including whether Muslims in New Jersey cheered the Sept. 11, 2001 terrorist attacks.

Part of the problem is that Trump and his candidacy are to some extent a creation of the mainstream media. At the very least, the two have developed a disturbingly co-dependent relationship.

The unpleasant reality is that Trump makes great fodder for newspapers and news websites. Anything involving his wacky pronouncements and semi-racist invective is guaranteed to generate massive page views. Given that, there is no incentive to ignore him or challenge his remarks. Which could be why his claims about violence within the black community were called “questionable” and “controversial” instead of “a lie.”

CNN figures out a way a to avoid saying that Donald Trump lies https://t.co/H2fLeRepEy (via @AntDeRosa)

— Judd Legum (@JuddLegum) November 23, 2015

Even The Huffington Post, which said it was going to relegate Trump to the entertainment section, appears to have given in. As communications professor Michelle Amazeen told The Daily Beast:

“The incentive for candidates [to lie] is that most media outlets don’t have the resources to check for accuracy immediately,” Amazeen said. “But since the U.S. news media is based on the commercial model—and more eyeballs on the page or the screen is good for business—the networks love it when someone like Donald Trump says outrageous stuff. Fact-checking rains on the parade of that revenue model.”

Another factor is the traditional media approach of emphasizing objectivity and artificial balance in news coverage—what James Carey at Columbia University calls “false equivalency” and New York University professor Jay Rosen refers to as “the View from Nowhere.” As media researcher Nikki Usher put it in a recent Medium post:

“The reporting is detached rather than a full-fledged and necessary assault on some of the worst racism we’ve ever heard from a national political figure. Trump is just making things up and no one is actually calling him on it directly in the name of objective reporting.”

So if a news source is writing about Trump and his claim that Muslims cheered the fall of the twin towers on Sept. 11, then it more or less has to take the idea seriously because he is a presidential candidate. At best, it might be able to find someone to refute the fact, but even doing this lends an artificial air of legitimacy. Only in an editorial can a newspaper come right out and say it’s a lie.

We’ve seen this movie before, to a certain extent. During the last election campaign, fact-checking of candidates also became an issue, in part because former New York Times public editor Arthur Brisbane wrote a piece asking whether journalists should be expected to be “truth vigilantes” when it comes to political remarks.

Not surprisingly, there was some backlash to this question. Shouldn’t all journalists be “truth vigilantes?” Isn’t fact-checking and truth-telling what journalism is supposed to be about in the first place? The big problem is the effect that might have on the aforementioned page-view generation potential of candidates like Trump, along with the kind of coverage that treats an election like a horse race.

For whatever reason, hard-headed fact-checking appears to be left to sites like Politifact and FactCheck.org, where statements like Trump’s comment about New Jersey Muslims gets a “Pants on Fire” rating.

Are news outlets so concerned about being seen as partisan that they don’t want to challenge such statements directly? If so, that’s yet another strike against the false objectivity standard. Or is it that political coverage is seen as a game, and Trump just another contestant, and therefore no one is expected to take such comments seriously? That doesn’t say much for the media’s role as social benefactor.

You can follow Mathew Ingram on Twitter at @mathewi, and read all of his posts here or via his RSS feed. And please subscribe to Data Sheet, Fortune’s daily newsletter on the business of technology.