Having made themselves so unpopular, Malcolm Turnbull and Bill Shorten will have only themselves to blame if the Greens emerge from this election more powerful than ever, writes Terry Barnes.

A week-and-a-half into this election campaign, Prime Minister Malcolm Turnbull and Opposition leader Bill Shorten have had some tough challenges.

Turnbull has not quite found his rhythm, dogged by residual fallout from his leadership coup against Tony Abbott last September; he's under pressure from both Labor and conservative think-tank, the Institute of Public Affairs, on superannuation changes in the budget; and yesterday the Government back-flipped with pike on the "backpackers' tax", punching a $40 million hole in the Coalition's debt-laden forward estimates.

Then there's the small matter of shadow Opposition leader, Peta Credlin.

Shorten, too, has struggled. While starting better than Turnbull, Shorten has dealt with candidate after candidate's ambivalence about Labor's "me too" policies on border protection and mandatory detention. He lost another candidate in the safe Labor seat of Fremantle to an undeclared criminal record. On protecting weekend penalty rates, this week Labor has looked decidedly ragged, with more positions than the Kama Sutra.

Even Labor's campaign battle-bus had a bingle.

All the while, the one party leader scrubbing up well is the Australian Greens' Senator Richard Di Natale.

Had this election been for half rather than the full Senate, the Greens would be in trouble. They would have been hard-pressed to maintain their 10 senators in a half-Senate election, but Turnbull's double dissolution makes their task easier.

Currently, the Greens stand to do much better than 10, at least on paper. The headline of the Morgan poll released this week was Labor gaining an election-winning two party-preferred lead of 52.5 to 47.5 per cent. Its real story, however, is in the primary vote: the Coalition's collapsed by 3.5 per cent, but Labor's barely moved. The big winner was the Greens, increasing their primary support by two points to 15.5 per cent.

Spread uniformly in a double dissolution poll, on that vote the Greens could win at least two seats in each state, with Labor and other preferences potentially garnering it several more. Possible peaking aside, that puts them on track to regain de facto control of the Senate from the fruit loop crossbench.

Add to that there's a concerted Green push to take House of Representatives seats off Labor - notably Batman and Wills in Victoria, and potential Shorten successor Anthony Albanese's Sydney seat of Grayndler. The Greens also are making their presence felt in affluent Liberal seats like Melbourne's Kooyong and Higgins, with well-heeled voters attracted by their feel-good social, environmental and humanitarian messages.

Above all, the Greens look almost respectable rather than the traditional rabble of tree-huggers, angry activists and hemp sandal-wearers of yore.

Di Natale, a GP, appears solid and dependable in his 1940s-style suit and waistcoat. Melbourne MP Adam Bandt, with his designer glasses and smart suits, looks like a partner from a major consulting house. Queensland's Larissa Waters was a lawyer, Tasmania's Peter Whish-Wilson was a merchant banker, and Nick McKim was a minister in a Tasmanian Labor-Greens coalition government.

Yes, they do have "Old Greens" in their ranks like Sarah Hanson-Young from South Australia and Lee Rhiannon from NSW. But the Greens as a parliamentary force has a newfound ring of mainstream respectability making many swinging voters give them a second look, and major dissatisfaction with both Turnbull's Coalition and Shorten's Labor gives the Di Natale Greens even more cred.

Furthermore, Di Natale is playing his hand well. He's got Labor in a tizz by insisting the Greens will assert their balance of power and agenda, and Shorten felt compelled to sign a pledge demanded by the Daily Telegraph newspaper to not enter a coalition with them.

The Liberals, on the other hand, are tangled over preferencing the Greens to defeat Labor in its vulnerable inner-city seats. Senior party officials have not yet fully ruled out playing footsies with a party whose values not only are the antithesis of Liberal values, but whose leader Di Natale emphatically said the Greens would never support a minority Liberal government, and which since 2013 has opposed bill after Coalition bill in the Senate and fuelled the chaos of the outgoing parliament. Many grassroots Liberals are having conniptions over such pointless party games.

Even controversy about whether Di Natale should be included in the leaders' debates plays into Green hands. If they win a place on the stage they can portray themselves as serious contenders; if they don't they can say the major parties are scared of them.

The beauty of this overall Green campaign strategy is it builds electoral support, and their post-election power base, while dodging scrutiny of the substance of their policies.

A simple look at their very slick website, however, shows the party may market itself as New Green, but underneath it's Old Green through and through.

Green policies are still big government tax and spend. Wealth-generating big business is still a class enemy. Saving the economy runs a distant second to saving the environment. And when it comes to offering fiscal responsibility and savings of any sort, it's about spending more and cutting nothing: the Greens' traditional fondness for magic pudding economics and exercising power without responsibility haven't gone anywhere. Appearances are deceptive.

How a Green policy agenda will be paid for hasn't been properly explained, and don't expect it. They may have cloaked themselves with respectability, but are still the anti-capitalist economic and political wreckers they have been since Bob Brown and Christine Milne's time. Like the Sirens of classical legend, their song belies their danger.

The Greens are out-campaigning both the Coalition and Labor, and come July they may yet impose a heavy price on Australia's economic and political stability.

But, having made themselves so unpopular, and not as yet laying a glove on Di Natale and Co., Turnbull and Shorten have only themselves to blame if the Greens emerge from this election more numerically and politically powerful than they ever have been before.

Terry Barnes is a policy consultant, former senior adviser to Tony Abbott and writes weekly for The Drum. Twitter: @TerryBarnes5