And they must hope he has a plan to combat it.
After all, in less than 18 months, Trump managed to beat not just the Bush political dynasty and another 10 Republican candidates, but also the ruthless and formidable Clinton machine.
Every student of politics — and Ardern is certainly that — has considered carefully what can be learned from Trump's success.
First, and most important, is to bypass the serious media and speak directly to voters.
Trump openly mocks the establishment media. Ardern is friendly, but it clearly matters very little to her politically when New Zealand's longest serving and most respected political scribes say she has a habit of creating the wrong impression.
As Trump turns to the likes of Sean Hannity and Fox News, Ardern can call upon her friends embedded across the popular media to present her actions and statements in the best possible light or, better still, crack a good joke.
The second similarity with Trump is that facts simply don't matter to Ardern's political appeal.
Again, Trump is bolder, confident telling outright lies.
With Ardern, statements are made that are not intended to be taken literally, such as her target of reducing suicides to zero or her declaration to the UN this week that the goal must be that the local school should be the best in the world for every child.
Ardern insisted to New Zealand media that baby Neve's privacy should be respected, including through an informal agreement that her face always be obscured in photographs.
But this did not stop Ardern and her partner Clarke Gayford using Neve to make a political point in perhaps the most public place in the world — the floor of the General Assembly of the United Nations in New York.
On more substantial matters, such as oil and gas, it was obvious Ardern's exploration ban would reduce GDP and increase global greenhouse emissions, but her failure to ask for any analysis ahead of the announcement meant it could be positioned as the opposite.
On the conduct of Government, it is enough for the regime to declare it will be the most open and transparent ever, even though its practice has already managed to outdo John Key's for opacity.
Such flagrancy works for both Trump and Ardern because what counts to their supporters is that their hero's statements touch base with their feelings, not that they stand up to scrutiny.
These factors also protect Trump and Ardern from criticism on ethical grounds.
By no stretch is Ardern as personally ethically challenged as Trump. Nevertheless, after initially hesitating, she has had to get rid of two ministers in less than a month.
The first, Clare Curran, for repeated failures to be upfront with the public, and the second, Meka Whaitiri, for allegedly causing bruising to a member of staff during a heated exchange.
As with Trump, none of these scandals make any difference to Ardern.
Still, there is no more point in Bridges whinging about any of this than there was of Labour MPs complaining that Key and his Government were forgiven so readily for everything from the Sky City affair, to the Saudi sheep deal, to Key's own incident with a waitress and her ponytail.
Bridges needs to accept this is the world in which he is operating, and act accordingly.
The first step would be to resist the urge to take seemingly random positions on every issue that comes along.
National's recent scattergun approach to victims of the meth contamination hysteria, the protection of imported Himalyan thars, and its attitude towards Trump himself has looked more like a midnight tweet-storm than a serious strategy to win back the Beehive.
- Matthew Hooton is managing director of PR and corporate affairs firm Exceltium.
