Who could have imagined, eight years ago, that George W Bush would emerge as a rallying point for the American left?

And yet, in the past 24 hours, that is precisely what has happened, as Bush delivered a speech pretty obviously aimed at criticising Donald Trump. He warned of “nationalism distorted into nativism”, of “isolationist sentiments”, and said that America had to recover its own identity.

Bush is no hero, and his comments should do nothing to redeem his presidential reputation. He was a bad president, and the final scoresheet may yet find that he did more damage than Trump manages to. But his speech, and its reception, is an important sign of how much has changed in America, and in the world, and how quickly. The appeals of a rational incompetent president over an irrational incompetent president are obvious.

One of Bush’s warnings was this: “Our politics seems more vulnerable to conspiracy theories and outright fabrication.”

I mention this because there has been much jollity around the embarrassment of Foreign Minister Julie Bishop by the election of a Labour government in New Zealand. The incident itself is a storm in a thimble because, as everyone knows, it was just a dumb political episode and the trans-Tasman relationship is dandy.

If you’ve forgotten why Bishop should be embarrassed, it’s because back in August she had taken aim at New Zealand Labour over the involvement of one of its MPs in helping Australian Labor on the Barnaby Joyce citizenship front. She went in pretty hard, so the election of a Labour government, with which she will have to work, might seem a little awkward for her.

But Bishop herself shows no sign of embarrassment. In a series of tweets replying to journalists who were reminding readers of the incident (“Pity we said all those things about not being able to trust New Zealand Labour”, “Don't forget it was @JulieBishopMP who had some pretty harsh words to say about the potential of a NZ Labour government”), Bishop insisted they were “Rubbish”, and demanded journalists “Read what I actually said”, going on to say she agreed with the new prime minister’s admonishment of her colleague.

The problem for Bishop is that the journalists had read what she actually said, and were accurate in their appraisal. As I pointed out in September, Bishop’s first comment was hedged, aimed only at the MP involved. But then Bishop overstepped, as she has a bad habit of doing, and threw her net over the whole party: “I would find it very difficult to build trust with members of a political party that had been used by the Australian Labor Party to seek to undermine the Australian government.” You can read the transcript here, on Bishop’s official ministerial website.

Bishop shouldn’t be forced to suffer the indignity of all this alone. Malcolm Turnbull himself talked of the two Labor/Labour parties conspiring to bring down his government, as did Christopher Pyne. The attack itself was no doubt sanctioned by the PM. But it was only Bishop who spent her time today publicly denying she had said what she had undeniably said.

Now, remember what George W said? “Our politics seems more vulnerable to conspiracy theories and outright fabrication.” Exactly the two ingredients we’ve seen in this ridiculous episode.

Earlier this week I wrote about Malcolm Turnbull’s frustration with journalists asking him to “guarantee” cuts to power bills. I can understand this, because everyone knows price falls can’t be guaranteed. But I also firmly believe that journalists are justified in asking the question, because the government tries very hard to create the impression the price falls are guaranteed. To put this another way, politicians cannot complain about a low standard of debate they have done much to create.

Politicians love to complain about the media, but they need to understand their role in shaping the parameters of public discussion. When they attack reporters for “fake news” over stories that they simply don’t like or disagree with – something we’ve seen done by both Labor and Liberal politicians – they blur the line between legitimate media and trolls. They smooth public debate into a blancmange where there is no difference between falsehood and truth. The same goes for a foreign minister going after the media for accurately reporting her words.