Isaac Newton's Third Law of Motion doesn't apply to Australian politics — ''For every action, there is an equal and opposite reaction''. But Julia Gillard might have changed that.
There's a good chance Gillard's legacy will not be what she did, or what she attempted to do as PM. Instead her legacy will be what she prompted an Abbott government to do.
In Australian politics, once something is decided, it tends to stay that way. The massive increase in the size of government under Gough Whitlam wasn't reversed by Malcolm Fraser. The economic liberalisation of the 1980s of Bob Hawke and Paul Keating certainly wasn't going to be reversed by the Coalition, and even Wayne Swan, try as he might, can't unfloat the dollar. The GST reform of John Howard and Peter Costello hasn't been touched by Labor.
But when it comes to the Gillard government, the situation is very different. So many of its policies have been so bad or so deeply unpopular, there's simply no way they will be perpetuated by an Abbott government. For example, no major political party will enter into an alliance with the Greens any time in the foreseeable future.
Kevin Rudd and then Gillard destroyed (fortunately) any chance for Australia to have an emissions trading scheme or a carbon tax that will last beyond the life of this government. If Tony Abbott's promise to repeal the carbon tax can't be carried through the Senate if the Coalition wins the election, he'll have to risk his government in a double dissolution.
How climate change policy could have come to this, given that a few years ago emissions trading was bipartisan policy, is a question analysts will be asking for years.
On industrial relations there will be no return to Work Choices, or even pre-Work Choices from the Coalition (unfortunately).
Instead, the focus will be redirected to the operations of trade unions themselves. Every aspect of trade union administration and governance will be scrutinised and legislated like never before. The sort of regulations the Labor Party has imposed on company directors will be visited by the Coalition upon trade union bosses. If any trade union leader wants to know what life will be like, they only need to ask directors of public companies how much of their time is devoted to compliance and reporting and box-ticking.
And trade union leaders can contemplate facing the sort of personal liability company directors must deal with.
Under an Abbott government, there will be some form of National Disability Insurance Scheme — but it will be radically different from what Gillard contemplated. It will be smaller, for the simple reason that an Abbott government won't have the money to fulfil Labor's promises. A future NDIS is also likely to be run by the states, not Canberra, so the structure of the scheme will be developed incrementally.
Under a Coalition government, the Gonski committee's ''reforms'' to school education will be dumped (fortunately). The setting up of the Gonski inquiry was a favour to teachers' unions from the Labor government. The committee's report was also a gift to these unions — the extra money the committee wants to spend on schools will go to hiring more teachers, not paying the best teachers more.
There's something else Gillard has provoked in the Coalition. She's succeeded in stirring up an appreciation that there's popular support to be gained for a political party that defends basic freedoms, like freedom of speech. MPs on both sides of politics were genuinely surprised by the reaction of the public to the government's Human Rights and Anti-Discrimination Bill. The bill would have been made it unlawful to express a political opinion that offended someone.
Public outrage caused Attorney-General Mark Dreyfus to abandon the bill on Wednesday. Then, on Thursday, Stephen Conroy renounced his plans to impose new government regulation on the media. The Coalition's George Brandis and Malcolm Turnbull mounted fierce opposition to both.
If Gillard ends up prompting from Tony Abbott an equal and opposite reaction to what she's done as Prime Minister, her legacy might not be entirely negative.