Optimism soared. Public expectations swelled to levels not seen since the 2007 "Rudd-slide".

Tony Abbott held a late night press conference to announce the Coalition would hold a plebiscite or referendum on same-sex marriage. Credit:Andrew Meares

In a triumph of hope over reality, voters overlooked that he carried the same party room as Abbott. And many even ignored the specific revelation that in order to salve reactionaries within, he had capitulated, agreeing to Abbott's transparently cynical denial of marriage equality.

The form of that denial, a lame camel that had limped from a shambolic talkfest in the joint party room, bound Liberals to the current definition of marriage. A deliberately vague "plebiscite" would follow at some point. Doubtless, Abbott would have insisted on a formal referendum – with its near-impossible bar for success – had that been an option. But it wasn't. No constitutional amendment was necessary. The Parliament was, and is, entirely responsible. End of story.

Yet under Abbott's model, now legitimised by Turnbull, the nation's 226 federal parliamentarians would take the pay but shirk the responsibility. Spurious rhetorical arguments would ask what could be wrong with letting the people decide? And conservative hardliners would flag their intention to ignore a pro-change result in the Parliament.