If he's to make sufficient progress with controlling the budget and reforming the economy to warrant re-election in three years' time, he needs to mix budget restraint with fairness, and combine efficiency with equity.
This, after all, was the formula the Hawke-Keating government used to stay in government for 13 years, despite all the things it did to get the budget back to surplus after the deep recession of the early 1980s and all the controversial reforms it made to open up the economy.
Remember that the people with the most reservations about those reforms – deregulating the banks, floating the dollar, removing protection – were its own supporters.
Only much later did Labor's true believers adopt Paul Keating as one of their heroes. And it was only by making uncharacteristic changes that Hawke-Keating came to be remembered as one of our greatest governments.
The people making trouble for Turnbull within the Liberals seem to have learnt none of that. They haven't even learnt the lesson of their latest near-death experience: low and middle income-earners won't vote for you in sufficient numbers if they suspect you don't represent their interests.
It's much easier to argue that Turnbull lost votes because his party had pushed him too far to the right than because he wasn't as far to the right as a noisy minority thought he should be.
Turnbull lost votes partly because, to get the party's permission to rescue it from certain defeat under Tony Abbott, he had to agree to leave untouched various extreme policies the whole country knew he didn't believe in.
Labor's Medi-scare was effective because Abbott's attempt to dismantle bulk-billing with his $7 co-payment exposed the party's lifelong antipathy to Medicare that a chastened and wiser John Howard had cloaked with his claim that the Libs were the best friend Medicare ever had.
Turnbull's policy for the reform of superannuation tax concessions was the epitome of the carefully balanced policies we need more of if we're to have reform without fear of electoral defeat.
It was a micro reform in that it reduced the tax system's distortion of saving choices, and it will contribute significantly to reducing the budget deficit, but do so in a way that reduces the concession to the undeserving well-off (including me) while making the scheme fairer to low income-earners and women.
And yet the Liberal dissidents' greatest push is to modify the super reforms in favour of a relative handful of high-flyers. If Turnbull – and the more moderate, sensible elements of the parliamentary party – let this push succeed there could be no better demonstration of the party's instability and its continuing commitment to governing in favour of its well-off cronies, not ordinary voters.
The first rule of Australian politics is that Aussies won't vote for extreme parties. That's why, over the decades, both sides have moved towards the middle ground.
But it's remarkable to realise that, while Labor has been working hard to house-train its left wing, the Libs have been drifting further to the right, allowing extremists to dominate its state branches and more and more hard-liners to be elected to the parliamentary party.
Although the pragmatist faction still has most adherents in Parliament, much of the party is now out of step with the community on social issues and obsessed with furthering the economic interests of the well-off, not the punters.
Too many in the party have become self-indulgent and inward-looking. Let's play favourites between Tony and Malcolm. Let's let the old men continue blocking the talented young and the female. Let's make the party utterly unattractive to the younger generation.
In short, too many in the party have lost touch with electoral reality. In this they've been led astray by noisiness of their media cheer squad and the libertarian think-tanks. The Murdoch press has yet again demonstrated its inability to deliver the tabloid voter.
In this election the Coalition stuck its neck out by making an unpopular cut in company tax its main policy proposal. And yet big business seems to have failed to offer much support in the way of donations.
If that doesn't give the Liberals pause for thought, nothing will. Apparently, big business thinks itself so virtuous – so synonymous with the nation's interests – that even the Libs owe it a living.