Malcolm Turnbull has a bit more in common with Julia Gillard than he would like to acknowledge.

Both leaders took over from elected prime ministers between elections, via partyroom coups. Both started out popular only to fumble that goodwill by early into their respective election campaigns. And both, courtesy of their short-cuts to office, were exposed as light on for the leadership smarts and full-depth authority needed to dominate their parties, and project their genuine selves to voters.

In many ways, what went wrong for Gillard - notwithstanding Kevin Rudd's role -  is what is currently going sideways for Turnbull. It's the authenticity question.

Gillard of course, mismanaged the above problems spectacularly, eventually announcing mid-campaign, that voters would get the "real Julia" from then on. It was a serious error of judgment. On top of explicitly telling the citizenry that it had been deceived, it is hard to remember a more blatant admission of campaign failure. Nor a more pointless public declaration of a tactical shift.

Turnbull will not repeat that mistake, presumably. But he's skating close to a few others. Gillard's campaign fakery resonated badly with an electorate already incredulous over her stance against marriage equality - transparently a ploy to neutralise the Christian right within and beyond her party.

Gay marriage may not have been a central issue in 2010, but her steadfast opposition simply never rang true. Voters didn't believe her, which dented her credibility and eroded confidence in what she really stood for. Likewise on climate change. Gillard proposed a lame 150-member citizens' assembly to design a new ETS, despite promising to address the problem of policy drift under Rudd as a key justification for knocking him over.

Turnbull's descent has been remarkable with Monday's Newspoll showing that for the first time more than half of voters are dissatisfied - a 28 point plunge since November 2015.

Amazingly, some of the causes are the ones which also brought Gillard low. While he is a known supporter of marriage equality, he has simply stopped fighting for it as part of a squalid deal with his own right wing. An even bigger abandonment is in his signature commitment to climate policy, which has been handed over to a largely hostile party - all so Turnbull can hold his deal together.

Said a self-described Liberal Party member in Eden-Monaro, after expressing "disappointment": "I'm hoping that after the election, the Malcolm Turnbull we knew before will be back." Perhaps, but what personal mandate would he have if he has not even mentioned "his" issues during the campaign?

Besides, the rate of Turnbull's fall suggests he might want to unveil the "Real Malcolm" before that. Without explicitly naming it, of course.

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