Malcolm Turnbull, of all people, has washed his hands of the long-enjoyed political consensus about where we'd like the country to go. Credit:Andrew Meares Sure, the Nationals retain a whiff of agrarian socialism about them and some members would not feel out of place in a One Nation meeting, but the party is not overtly sectarian and racist, it is not anti-immigration, there is a grasp of free market economics, the leader is not so hare-brained as to be an avowed Trump supporter, happy to say nice things about Putin if The Donald does. By supping with One Nation, sharing the cutlery, and pretending the WA deal is nothing to do with him, Turnbull and those more explicit in their One Nation support have put the petty prize of power ahead of the nation and the certainties we've relied on, the things that have genuinely made us great. After the July election, I stumbled on a neat balance in Australian politics. If you accept that our modern era started in 1972, we've had nearly equal periods of Liberal and Labor prime ministers. The outcome, sometimes by good management, sometimes by luck, has been to deliver a nation that remains on any measure among the top handful of places the average person might want to live. Those rusted on to either side of politics will be sure we could be even better off if their side had a greater share of power, but only the churlish or the increasingly self-deceived could hold that we are not in a very good place, relatively speaking. Given our gifts, we should be capable of better and we will need to try harder to maintain and improve our quality of life. The current drift in meeting our policy challenges is doing our future no favours. Much worse than the drift though is the certainty that the simplistic populism of One Nation offers no answers for those challenges, that veering in One Nation's direction – grasping power at any price – will only reduce us.

When the coalition leadership lacks the spine to even call out George Christensen and Cory Bernardi, pictured, for supporting the rabid Q Society, there is no leadership. Credit:Alex Ellinghausen Turnbull's implicit support for preferencing One Nation ahead of the Nationals is the conclusive step in a drift away from a rational consensus. It's a small step from the fanatical climate change denialism of One Nation's Malcolm Roberts to the federal Treasurer proffering a parliamentary lump of coal as the answer to our energy needs. It's another small step from "stopping the stopped boats" and denigrating asylum seekers as "illegal immigrants" to One Nation's overt sectarianism and the anti-immigration, small-Australia brigade. When the coalition leadership lacks the spine to even call out George Christensen and Cory Bernardi for supporting the rabid Q Society, there is no leadership. The drift of the leadership void will increasingly damage our economy. Weak or non-existent leadership will not be capable of dealing with the Reserve Bank's suggested to-do list if Australia is to progress. The lack of certainty over a credible carbon policy is an obvious problem for business. The coal lobby might be cheering the Coalition/One Nation stand, but the rest of Australian business is not when the outlook is for more expensive energy. Who wants to invest in a country whose government forsakes all scientific advice on secure and sustainable energy?

With so much else going for us – natural resources, an educated and adaptable workforce, proximity to Asia, an open society, growing population, strong institutions and political stability – Australia hasn't had to bribe investors with especially low corporate tax rates. You don't need to sell on price when you offer quality. We've been the country that could have five prime ministers in six years and still turn a politically stable face to the world. Who the prime minister might be this week or which party is in power hasn't mattered nearly as much as we sometimes think when the parties are on the same broad page. With the slide of the Turnbull government to One Nation partnership and mollycoddling of the far right, that can no longer be taken for granted. Labor's flirtation with the Greens finished up doing it and the country no favours, but the hard right now poses a bigger threat when it tears at the coalition. Loading The Australian economy's immediate challenge is tepid non-mining investment. Under Liberal and Labor governments of the modern era, investors could rely on a commitment to growth, an optimism about our strengths and opportunities. Bowing to the protectionists, the populists, the narrow-minded and simply barmy comes at a cost to that confidence.

Government at any price is the lowest common denominator of politics. The nation ends up paying for it.