What truths cannot be uttered on the left? Just as there are things that can never be admitted on the right, so too are there unmentionable things on the other side.

If there are certain truths that cannot be uttered on the right, even by the Prime Minister, for fear of upsetting people, there are similarly facts that no one can utter on the left without incurring the collective wrath of their ideological colleagues. Here they are:

1. “Stopping the boats” was a huge success in terms of preventing loss of life among asylum seekers.

The great unmentionable of the left: Operation Sovereign Borders not merely stopped the boats, it stopped asylum seekers drowning and restored confidence to Australia’s border control. Attempts to claim it merely shifted drownings elsewhere have never been borne out.

2. Labor was wrong on the GST and we have an inferior tax system to show for it.

In 1993 Keating declared the election was a referendum on the GST and if the Liberals won, Labor wouldn’t oppose it. Kim Beazley failed to do the same in 1998 and Labor’s opposition gave us Meg Lees’ nanny state GST.

3. Capitalism has lifted hundreds of millions of people out of poverty around the world.

While capitalism wears the blame for pretty much everything wrong in the world, it gets no credit for the rise out of dire poverty for hundreds of millions of people around the world, particularly but not only in China.

Thanks for signing up We look forward to seeing you bright and early with your need-to-know talking points and tidbits for the day ahead. Get Crikey FREE to your inbox every weekday morning with the Crikey Worm. Please enter your email address Sign up

4. The left doesn’t trust working class people with their own money.

The left are all for empowering low-income Australians and ensuring they have a decent standard of living — and rightly condemning racist income management policies imposed on Indigenous Australians. But if working class people choose to gamble, drink, smoke or consume sugar, the cry for bans, taxes and regulation to prevent them immediately goes up.

5. Protectionism doesn’t work.

The side of politics that began the process of ending Australia’s reliance on manufacturing protectionism is now the side of politics that supports it most strongly, at the cost of billions to taxpayers. And the Greens are even worse.

6. The Coalition is now closer to the basic Gonski school funding model than Labor or the Greens.

In both lifting funding for schools and in bravely taking on the Catholic school system over its lies about funding cuts, the Coalition has — after many backflips — arrived at a position closer to the original Gonski blueprint of needs-based funding with reallocation away from private schools than the left’s “everyone gets more money” version.

7. NIMBYism and anti-development sentimentality isn’t an infrastructure plan.

While most politicians surrender to NIMBYism at some stage out of electoral calculation (see Anthony Albanese backflipping on Westconnex in Sydney), it has an institutional home among Greens and state Labor parties in opposition, demonstrated most vividly by the rampant anti-development mentality on display in NSW at local council and state level. The victims: low income earners and young people unable to access decent housing near economic opportunity.

8. Trump is legitimate.

He didn’t win the popular vote … Russia helped him win … he used fake news and Cambridge Analytica … All those things are true. Maybe James Comey’s decision helped as well. But they made no difference to the result — Trump won by tapping into a mood of white grievance and exploiting the fact that Hillary Clinton was an inept, business-as-usual candidate with a poor ground game. Trump is a disaster as president, but he won fair and square. Deal with it.

9. 18C should be changed.

It’s a lower-order issue among many in the challenges to free speech in Australia (most of which have come from the right and corporations) but 18C is a sloppily-worded restriction on free speech that could be significantly improved by removing the concept that merely giving offence is grounds for prosecution and lifting the threshold to vilification.

10. Socialism has been tried and no it didn’t work.

No, Venezuela’s failure is not the result of “state capitalism”. Yes the Soviet Union really did implement socialism. No, it’s not true that socialism has never been properly tried. The far left’s favourite shifting of the goalposts aims to wish away a century of efforts by political parties to implement socialism — and the enthusiasm and apologetics of previous generations of left-wingers, who hailed the Soviet Union as true socialism — and declare that if only we did it properly it would work. Sorry.