When Tony Abbott suddenly declared the push for marriage equality to be "an important issue" last year – breaking with the political right's belittling of it as a boutique pre-occupation of inner-city "luvvies" – it was tempting to imagine the Coalition had undergone an epiphany.

It's a neat pre-election trick in which the Coalition is taking the political dividend of appearing modern and progressive, while studiously avoiding discussion of critical details of its plebiscite. 

At the very least it seemed, there had been a pragmatic recognition that continued resistance was becoming pointless or even counter-productive.

Yet Abbott's subsequent manoeuvrings showed the language change was nothing morethan that – a language change, cynically designed to manage that political pressure and to give the impression of progress while ensuring there was none.

That was before a substantive change of leadership brought the installation of the pro-equality, pro-free vote Malcolm Turnbull.

Yet such was the party room passion for the status quo that Turnbull was forced to expressly trade off his preference for a swift parliamentary determination in his Faustian pact with the party's conservative core.

Since then, the government has done a pretty serviceable job of having it both ways by being pro-plebiscite, yet anti-detail. An optimistic Turnbull sells the prospect of reform as all but inevitable, and has been allowed to get within days of the election without explaining why he believes so firmly that a plebiscite will succeed and why his party, the majority of which is against any change, will seamlessly back its outcome.

As we know, many will not.

Turnbull believes the arguments for equality will be publicly compelling but has been reluctant to outline them pre-election for fear of exciting reaction from reactionaries within.