Conservative backlash Tony Abbott led the Liberals back to power. Until Malcolm Turnbull does the same, he will be on probation with the party faithful.
One of the surest maxims about politics is that divided parties don't win elections. Malcolm Turnbull has just divided the Liberal Party and taken control of it by the same action: staging a successful rebellion against Tony Abbott.
He won but he did so against 45 per cent of his parliamentary colleagues and a much larger percentage of Liberal Party members in the country. 
A good source tells me that telephone and internet messages into Canberra were running at well over the rate of 90 per cent for Abbott and against the parliamentary coup before and after the vote, with such messages as, "Are we mad?" and "We're as bad as Labor".
Electoral self-interest and party discipline will restrain and eventually pacify the disappointed former loyalists on the government benches.
A reluctant National Party has already pledged fealty to Turnbull. Abbott will not join any cabal bent on revenge from the right, as his angry but dignified statement on Tuesday made plain. And the approaching election will surely strengthen all the instincts of party unity.
But these cold, necessary, Machiavellian calculations won't greatly influence the Liberal rank and file who support a political party from tribal loyalty or ideological sympathy. Their discontent will have to be soothed, and their support will have to be won back by the new Prime Minister. It won't be easy.
After all, Abbott led the Liberals back into power. Until Turnbull equals or improves on that performance, he will be on probation. And the more decently Abbott behaves towards the usurper regime, the more he will become a figure of stoic nobility to the party faithful. (And not only to them. Even some media figures are starting to look guiltily embarrassed, but that will pass.)
So Turnbull has to solve a tricky problem. He has to heal the party divisions in the country and outperform Abbott in governing to win the election that will make him legitimate.
You might suppose from television news and satire shows that the Abbott government was such a universal failure that outperforming it would be child's play. Certainly the Abbott government had its flops. He disappointed his free-speech supporters on such matters as Section 18C censorship.
Having mishandled the selling of a tough first budget, he and Joe Hockey found that they had to soften and stretch out the economic reforms that the end of Australia's long boom made essential. And he was damaged by a succession of gaffes and "captain's picks", starting with Prince Philip's knighthood - though also by the constant drip of hostile leaks from within his cabinet.
On the big issues, however, the Abbott government stopped the boats, repealed carbon and mining taxes, reached free-trade agreements with Japan, South Korea, and China, and achieved 2 per cent growth in jobs in the face of difficult international trends, in particular Chinese instability.
Turnbull would probably not have stopped the boats or repealed the carbon tax in the first place. Now he proposes no change in those policies that have conveniently removed two massive obstacles from his path.
But the central budgetary problem - how to make necessary cuts in government spending without alienating key constituencies or penalising less-fortunate voters or meeting strong opposition from labour unions - remains as thorny as ever. Will Turnbull outperform the Abbott government on that? Can he?
There is a persistent myth in moderate conservative circles that big social and economic reforms that require abolishing restrictive practices or removing economic rents from powerful social groups can be achieved without serious conflict. What is required is consultation, reasonableness, a willingness to compromise, a change of "tone". That was the fall-back case that the "wets" mounted, mainly in retrospect, against Margaret Thatcher after her victories: what she wanted was fine but she went the wrong way about it.
This is self-deception. Powerful groups don't surrender their privileges - which they usually consider justified - without a fight. Turnbull knows that he will have to have that fight, maybe in the run-up to the election. He might well calculate that his socially progressive image will help him to win it with public opinion. But he will also need the united support of his party against a Labor Party fighting hard for the status quo of welfare and regulation.
As things are, however, Australian conservatism after Monday night is divided between the Liberal Party led by Turnbull and a broader conservative tendency that looks to John Howard and Tony Abbott for leadership and inspiration. Turnbull must win that tendency over. It's a different game to the one on Monday night.
And it isn't over.
John O'Sullivan is editor of Quadrant and a former special adviser to Margaret Thatcher.