US presidential election campaigns are usually noteworthy for the dirt that candidates throw at each other, and the latest one is running true to form.

But how do reporters who are doing their level best to tell their readers the truth cope when candidates move from spouting (just about acceptable) spin to telling (unacceptable) lies?

These problems are raised in a short piece in the New Republic by Alec MacGillis, The welfare card and the post-truth campaign.

He tells of witnessing a campaign appearance in Ohio by Mitt Romney in which the Republican candidate told his audience:

"I want you to know I heard something the other day that really surprised me... What I heard is that the president is taking the work requirement out of welfare. (Boos.) Yeah. We value work, our society which celebrates hard work, we look to a government to make it easier for jobs to be created and people to go to work. We do not look for a government that tries to find ways to provide for people who are not willing to work. And so I'm gonna put work back into welfare and make sure able-bodied people can get jobs."

Canvassing the crowd afterwards, MacGillis learned that Romney's anti-Obama welfare jibe was the favourite part of his address. He writes:

"One of the more depressing parts of the job of being a political reporter is watching an audience fully absorb a blatant and knowing lie. Which is, of course, what this is. Countless fact-checkers... have unequivocally rejected the assertion that Obama has ended the work requirement. His administration has instead granted more leeway to states, including several with Republican governors, to explore new ways to get people on to welfare into jobs."

As MacGillis notes, the welfare debate has been subject to rigorous fact-checking, and he cites a Washington Post example to prove his point. Yet Romney, his running mate Paul Ryan and Republican TV ads go on repeating the "utterly unfounded" attack on Obama's policy.

Worse. Despite the fact-checking process that is supposed to inform its journalism, America's press is not confronting Romney about his falsehood. He is being allowed to get away with it.

MacGillis's point is taken up by Garance Franke-Ruta at The Atlantic. She writes:

"Fact-checking was a great development in accountability journalism - but perhaps it's time for a new approach. It's no longer enough to outsource the fact-checking to the fact-checkers in a news environment where every story lives an independent life on the social web, and there's no guarantee the reader of any given report will ever see a bundled version of the news or the relevant fact-checking column, which could have been published months earlier. One-off fact-checking is no match for the repeated lie."

She puts her finger on the real problem. Repeated lies. This is a familiar device employed by politicians (and British popular newspaper editors), and it is always difficult to counter.

And there have been plenty of examples in the States. Franke-Ruta mentions one: Obama is a Muslim. And don't let's forget the crucial one about Saddam Husein being behind the 9/11 massacre.

She advocates the insertion of key sentences, or even paragraphs, in every story in which the lie is retailed. On the other hand, she appears to concede that this may not change the minds of the majority.

The problem is more acute in Britain because our newspapers do not have the kind of fact-checking common in the US press. Our papers are also unashamedly partisan, even advocating that "freedom" as a virtue.

Then again, we do have plurality and diversity - for the moment at least - in our mainstream media. We check up on each other. There are also many credible online and social media critics.

But lies still beat us. After all, we made war on Iraq because too many newspapers happily accepted the political lie that Hussein had weapons of mass destruction and was able to launch them within 45 minutes.

Sources: Scottish Review/The New Republic/Washington Post/The Atlantic