Same-sex marriage could be further away now than before. Credit:Wolter Peeters Indeed in promoting equality, this columnist has written more frequently and more critically than most against what was a blatant can-kicking exercise by Tony Abbott and fellow recalcitrants in 2015. What's more, this correspondent was advancing the arguments for marriage equality back when it was routinely brushed off by the major parties as a boutique concern of the inner-city latte set – something even Abbott stopped arguing last year. And this advocacy came, by the way, well before the Labor party, unlikely hero of the latest pyrrhic victory, finally showed the gumption to campaign against an unconscionable legal discrimination. Despite its obviously self-serving nature – denied publicly but acknowledged privately by senior Labor figures – the opposition's decision to block the plebiscite, was greeted last Tuesday with universal acclaim by the broad left including the LGBTI community, the ALP's activist base and that of the Greens.

At the heart of this unquestioning glee lay several critical miscalculations. Misunderstandings that are informed not so much by hard political realities, as by a mixture of naive optimism, and tribalism. Principal among these is the failure to imbibe the internal politics of the Coalition and, most pointedly, the totemic, even existential, significance of the same-sex marriage question to Malcolm Turnbull's ongoing leadership. As is well known, Turnbull specifically agreed to retain Abbott's plebiscite as a condition of right-wing support for his promotion. It may seem shabby that the swift delivery of human rights to a whole class of persons has been traded away to sate the ambitions of one man, but this is what happened. From this misreading flows the next miscalculation: That Turnbull, after being publicly repudiated by his political enemies in the Parliament, simply rolls over and agrees to their free-conscience vote demand for Coalition MPs in the next few months. This won't happen. It seems supremely unlikely that Turnbull, having surrendered SSM to secure the leadership, would suddenly stake his leadership on rescuing it. A third miscalculation stems from another element of the left's high-mindedness: the inherently unprovable claim that a public plebiscite would unleash a vile tidal-wave such that sexually conflicted and alienated youths would suffer inordinately, and would in some cases take their own lives. Bill Shorten advances this argument and cites the advice of mental health expert Patrick McGorry. Turnbull has spoken to Professor McGorry also, and says he believes the debate can be had with minimal damage. Fourth, that the inevitable discomfort caused by the aforementioned hate-speech would be so profound that it would not be assuaged by the broad condemnation of said hate-speakers by civilised society. This harm amelioration led by the nation's political leaders, from Turnbull, Shorten, and Richard Di Natale, down to their parliamentary colleagues, could be very significant. It could even lead to the isolation of bigots and to a new inclusiveness in which LGBTI citizens feel increasingly and explicitly validated. Best-case scenario, admittedly.

Then there's the heroic claim made on behalf of LGBTI people that they would suffer more aggregate harm from a short, sharp public debate than they would from the continuation of legalised discrimination against them, potentially indefinitely. This balance-of-harm consideration is fundamental to the pro-and-con argument yet has been completely lost in the partisan politicking over the plebiscite. There's even a sixth element to consider if we're being exhaustive: the legitimacy question. Assume, for a moment, successful reform via the two paths: on the one hand, a narrow parliamentary conscience vote in favour of SSM, or, on the other, a parliamentary endorsement following a majority public vote – perhaps even by a significant margin. Leaving aside where you stood on what is a clearly flawed plebiscite, there is little doubt which mechanism would deliver the more robust result – the outcome least susceptible to a right-wing gainsay and therefore subsequent parliamentary revision. In the historic civil rights push of 1963-64, reformers including Martin Luther King accepted many compromises and imperfect procedures in service of their main aim. Such was their single-mindedness that, at one point, the liberal pro-civil rights Justice William Brennan even delayed a judicial decision advantageous to black rights by broadening the 14th amendment, lest it handed Congress an excuse to do nothing on the basis that the Supreme Court had relieved it of the burden. Nobody cared much about procedural compromises once core legal rights had been secured.

A lesson for same-sex couples who right now could be further away their goal of legal marriage than they thought a few months back. Mark Kenny is chief political correspondent.