Why does Australia stand alone in terms of being so retrograde on gay rights compared to the other Anglo countries like Canada, the UK, New Zealand and these days most parts of the U.S. as well?
It's not really the Australian populace that is opposed to gay marriage (
a recent poll showed that 72% of Australians support gay marriage, and that was six months ago, so support may have increased since then), but the strong influence of socially conservative unions within the ALP. A lot of people have speculated that Gillard's failure to support gay marriage was due to her need for the support of the socially conservative leader of the Shop, Distributive and Allied Employees Association, Joe de Bruyn. The ALP has also traditionally had a fairly culturally conservative Catholic base, though religious-based voting patterns have basically dwindled over recent years.
The NDP and the ALP are both members of the Socialist International, so I don't think it's
absurd to say they're sister parties.