Just to clarify:
It wasn’t a referendum. That would mean this was a change to the constitution (it wasn’t) and that politicians would have to implement the result (they weren’t obliged to).
It was a public opinion poll that wasn’t run by the electoral commission and was binding on exactly no-one. In other words, the politicians did whatever they wanted, unencumbered by any legal requirement to follow the poll results. Our former village-idiot Prime Minister, Abbott, voted the exact opposite of the way his electorate wanted him to.
The marriage act had been changed by Howard in 2004 to “a man and a woman”, with no reference to, or poll of, the public. It could have been changed back just as easily.
http://www.smh.com.au/articles/2004/05/27/1085461876842.html