While the ALP girds its loins for real debate and conference floor contention over the coming days, the prime minister’s handling of gay marriage is increasingly inexplicable.

The party’s national conference meets in the shadows of a European economic crisis and a possible global recession, but the likely political outcome of the conference will focus on the implications for Julia Gillard’s authority over the vote on same-sex marriage.

This is of her own doing. She has elevated this issue by publicly taking a hard line against gay marriage in favour of the do-nothing position of a conscience vote and no platform change, and by personally lobbying Right delegates to support her position. She is in effect challenging the conference to trash her authority, putting pressure on senior party figures to back her no matter what.

Rarely was prime ministerial authority deployed on a less significant electoral or national interest issue. Polls consistently show strong voter support for the right of same-sex couples to marry. But it’s not an issue that drives voting behaviour like health or education or the economy.

Perhaps Gillard miscalculated the determination of the Left not to settle for the position of a conscience vote and no platform change. But to deploy her shaky authority on the issue suggests misjudgment rather than miscalculation.

A more leader-like stance would have been to remain above the fray and not commit troops to a battle that, while of totemic significance to many in the party, holds none of the substance or electoral clout of issues like uranium or the economy. Now, she has much riding on the outcome of the conference vote and the willingness of factional leaders to hammer out a deal tonight or tomorrow that will spare prime ministerial blushes.

And in doing so, Gillard has firmly aligned herself with conservative forces within the party. The “compromise” of a conscience vote is no compromise at all, unless it is coupled with a platform change, since it guarantees no real-world consequences such as legislative change. This won’t endear her to the ever-diminishing party membership, and appear to confirm that Labor is no longer the vehicle of progressive social change.

According to Labor MPs, the issue of Gillard’s own relationship status is repeatedly raised by voters — if she has a strong personal belief in the status quo, why is she in a long-term relationship but not married herself? The prime minister’s personal circumstances are not an appropriate part of the debate, but it adds to the sense of confusion on the part of party members who’ve seen the government shift to the right on asylum seekers and, now, uranium.

A smart leader knows that some battles are won and some are lost, and it’s wise to keep your authority in reserve for the battles you need to win. Gillard didn’t need to win on same-s-x marriage, but now she does. If she loses, it’ll be yet another example of this government’s remarkable record of following up any success with a stuff-up of its own making.

If she wins, she’ll look like yet another obstacle to social reform to many within the party and in the electorate who don’t understand why gay couples continue to be treated as second-class citizens.