When Donald Trump began his run for the White House, many people treated it as a joke. Nothing he has done or said since makes him look better.

On the contrary, his policy ignorance has become even more striking, his positions more extreme, the flaws in his character more obvious, and he has repeatedly demonstrated a level of contempt for the truth that is unprecedented in American politics.

Yet while most polls suggest that he’s running behind in the general election, the margin isn’t overwhelming, and there’s still a real chance that he might win. How is that possible?

Awfulness

Part of the answer, I’d argue, is that voters don’t fully appreciate his awfulness. And the reason is that too much of the news media still can’t break with bothsidesism – the almost pathological determination to portray politicians and their programmes as being equally good or equally bad, no matter how ludicrous that pretence becomes.

Just to be clear, I’m not arguing that distorted news coverage is the whole story, that nobody would support Trumpism if the media were doing their job. The presumptive Republican nominee wouldn’t have gotten this far if he weren’t tapping into some deep resentments.

Furthermore, America is a deeply divided country, at least in its political life, and the great majority of Republicans will support their party’s nominee no matter what. Still, the fact is that voters who don’t have the time or inclination to do their own research, who get their news analysis from TV or regular news pages, are fed a daily diet of false equivalence.

This isn't a new phenomenon. During the 2000 campaign George W Bush was flatly dishonest about his policy proposals; his numbers didn't add up, and he claimed repeatedly that his tax cuts, which overwhelmingly favored the 1 percent, were aimed at the middle class.

Yet mainstream coverage never made this clear. In frustration, I wrote at the time that if a presidential candidate were to assert that the earth was flat, news analysis articles would have the headline “Shape of the planet: Both sides have a point.”

Balance

And Trump is far from being the only current political figure who benefits from the determination to find balance where none exists. Paul Ryan, the speaker of the House, has a reputation as a policy wonk, committed to fiscal responsibility, that is utterly incomprehensible if you look at the slapdash, fundamentally dishonest policy documents he actually puts out.

But the cult of balance requires that someone on the Republican side be portrayed as a serious, honest fiscal expert, so Ryan gets slotted into that role no matter how much a con man he may be in reality.

Still, there are con men, and then there are con men. You might think that Donald Trump, who lies so much that fact-checkers have a hard time keeping up, who keeps repeating falsehoods even after they’ve been proved wrong, and who combines all of this with a general level of thuggishness aimed in part at the press, would be too much even for the balance cultists to excuse.

But you would be wrong. To be fair, some reporters and news organisations try to point out Trump statements that are false, frightening, or both. All too often, however, they still try to maintain their treasured balance by devoting equal time –and, as far as readers and viewers can tell, equal or greater passion – to denouncing far less important misstatements from Hillary Clinton. In fact, surveys show that Clinton has, overall, received much more negative coverage than her opponent.

Threat

And in the last few days we’ve seen a spectacular demonstration of bothsidesism in action: an op-ed article from the incoming and outgoing heads of the White House Correspondents’ Association, with the headline “Trump, Clinton both threaten free press.” How so?

Well, Trump has selectively banned news organisations he considers hostile; he has also, although the op-ed didn’t mention it, attacked both those organisations and individual reporters, and refused to condemn supporters who, for example, have harassed reporters with anti-Semitic insults.

Equivalence

Meanwhile, while Clinton hasn’t done any of these things, and has a staff that readily responds to fact-checking questions, she doesn’t like to hold press conferences. Equivalence! Stung by criticism, the authors of the op-ed issued a statement denying that they had engaged in “false equivalency” – I guess saying that the candidates are acting “similarly” doesn’t mean saying that they are acting similarly. And they once again refused to indicate which candidate was behaving worse.

As I said, bothsidesism isn’t new, and it has always been an evasion of responsibility. But taking the position that “both sides do it” now, in the face of this campaign and this candidate, is an act of mind-boggling irresponsibility.