Many journalists view Trump as a high-risk demagogue - but is that a good enough excuse for them to throw their best-practice textbooks out of the window, asks Raymond Snoddy

American journalists wedded to a tradition of objectivity and impartiality that can seem suffocating to the British sensibility are asking themselves two big questions: How the hell can we be objective about Donald Trump - and should we be?

It is shades of Brexit all over again but on a gigantic scale - the winner of the US Presidential election gets their hands on the American nuclear button.

In the UK referendum campaign many national newspapers were ludicrously biased and became cheerleaders for leaving the European Union in a way that would shock many American journalists.

The BBC faced a more subtle challenge - and had to wrestle with its honourable tradition of impartiality, not always successfully or appropriately in the Brexit case.

But mainstream US journalism, once you get away from the crazy radio talk show hosts, takes objectivity very seriously and you sometimes feel they need at least two on-the-record quotes before they will claim that California is hot in the summer.

But how can you be objective about a man who says he wouldn't necessarily support a NATO ally under attack, who is an admirer of President Putin, who disrespects the family of a dead Muslim military officer and who wants to build a wall across the entire south of the US to keep out Mexicans?

As Jay Ruttenberg, the mediator of the New York Times put it this week: "If you are a working journalist and you believe that Donald J Trump is a demagogue playing to the nation's worst racist and nationalistic tendencies, that he cosies up to anti-American dictators and that he would be dangerous with control of the United States nuclear codes, how the heck are you going to cover him?"

The only answer for Ruttenberg is that you have to throw the traditional journalistic text book out of the window.

"But let's face it: Balance has been on vacation since Mr Trump stepped on his golden Trump tower escalator last year and declared his candidacy in the primaries and the caucuses," says Ruttenberg, who notes that the resulting imbalance resulted in Trump getting more than US$2 billion worth of free media - eight times more than his nearest Republican rival.

Now that he is the Republican candidate for President, what should the new journalistic textbook say about covering the Presidential race?

Part of the answer comes from Carolyn Ryan, the senior editor for politics at the New York Times, who promises that someone who so breaks the norms and assumptions of the American political system will continue to receive "copious and aggressive" coverage.

"It doesn't mean that we won't vigorously pursue reporting lines on Hilary Clinton - we are and we will," Ryan promises.

In fact, Clinton got it in the neck from the American media when she claimed on Fox News on Sunday that the FBI had found her answers on her private email accounts when she was Secretary of State to be "truthful" - a statement that was misleading at best.

Is this going to turn out to be a case of Brexit all over again, albeit a very different case in a very different country?"

Mrs Clinton later had to apologise for "short-circuiting" her answer.

It is Trump who has faced the main onslaught of negative stories - many of them self-generated. There has also been no shortage on a daily basis of American journalists going after the Trump record.

Newsweek has focused on his bankruptcies, deceptions and failures, and the Washington Post has dug out the fact that Carter Page Trump's main Russian adviser once invested in Gazprom, the Russian energy giant with close ties to the Russian government. Page has also been campaigning for lifting sanctions imposed on energy exports following the Crimean invasion.

Bloomberg Business Week has reported that Trump may have breached the Cuban trade embargo with his search for Cuban golf courses to develop.

And so the negative news on Trump goes on. Fifty Republican national security experts declared that Trump would be "the most reckless president in American history" while establishment Republicans seem to be queuing up to distance themselves from their candidate.

CNN has been doing regular fact-checking on the sayings of Donald Trump with considerable effect.

In his big economic speech in Detroit designed to "reset" a faltering campaign, Trump said that at 42 per cent - 36 per cent federal tax and 6 per cent local - American business was the most heavily taxed in the world and this was holding back growth.

Within minutes CNN specialists had concluded the claim on the tax percentages was correct but deeply misleading. Using legal tax concessions and off-shore operations, US businesses actually paid around one third of the headline figure and came in at the 60th most heavily taxed economy in the world - something very different from the Trump claim.

Does anyone care that the American media has discarded its textbook on objectivity? Isn't it all a plot by the liberal media to undermine Trump and all those experts again?

In some key swing industrial states white working class voters see Trump as "strong" and Hilary Clinton as a "politician" - and that term is not seen as a compliment.

Is this going to turn out to be a case of Brexit all over again, albeit a very different case in a very different country?

Are there international vapours of irrationality flowing from the disaffected and the left behind - people with genuine grievances kicking out at "politicians" but reaching for solutions that would almost certainly make things worse for them?

So far it's looking good for Hilary Clinton with the polls - ah the polls again - giving her a 10 point lead. It's early days and some may be shy in admitting to a potential Trump vote.

At least Donald J Trump will continue to be on the receiving end of copious and aggressive coverage that is not hamstrung by artificial concepts of objectivity and impartiality.