In March 2016, community support for same-sex marriage stood at its highest ever level, according to Essential Research’s polling: 64% of voters thought people of the same sex ought to be permitted to marry, while 26% believe they should not; 10% say they don’t know.

In comparison, in March 2011, support stood at 49% and opposition at 40%: there’s been a substantial shift in five years, from near-equal support/opposition to very strong community support — but who has shifted the most? Blue-collar men, it seems, have driven the shift from same-sex marriage as a marginally supported idea to one that commands nearly overwhelming community support.

For whatever reason, or gender stereotype, you prefer to name, men and women have long thought differently about same-sex marriage. Women have always been stronger supporters: in 2011, 56% of women supported it; now, 67% do. But men have shifted more substantially, from 43% support in 2011 to 62% now. Which men? The other big shift has been among Labor voters: there was a surge in Labor support for same-sex marriage in the July 2011 survey, which coincided with a push within Labor for the issue to be considered at its national conference in December that year (when then-prime minister Julia Gillard would be on the losing side on the issue) and a decision by New South Wales Labor to refer the issue to the national conference. What’s salient here is that the big rise in 2011 didn’t happen at the end of the year, when Labor changed its position to a conscience vote, but in the middle of the year, when the issue first began gathering media attention.

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The issue then lay dormant with Labor voters until after the election of the Abbott government, which was resolutely opposed to same-sex marriage.

In 2014, support among Labor voters rose again and, after a dip at the start of 2015, now stands at its highest level: 74% of Labor voters back same-sex marriage and just 18% oppose it, fully half of the 2011 level.

In the same period, support among Coalition voters hasn’t increased as much — but it has turned positive in net terms (approval minus disapproval), and is now into double figures in that regard. Just 40% of Coalition voters supported same-sex marriage (50% were opposed) in 2011 but now more than half — 52% — of Coalition voters support it, while opposition has dropped to 39%. There was a drop in support in August last year, when the issue split the government and led Tony Abbott to desperately craft the compromise of a plebiscite, but that didn’t last; Coalition support continued climbing afterward.

Greens voters have also strengthened their support — any opposition within Greens ranks virtually vanished in 2012, and now 94% of Greens voters support it, but given they only form around 10% of voters, that hasn’t contributed much to the overall rise.

But older voters have also strengthened their support. Younger voters were always strongly in favour of same-sex marriage but the majority of voters over 65 opposed it until recently. However, March 2016 was the first time more older voters supported it than not, 45% to 41% — an outcome likely to feed through into rising Coalition voter support, given the Coalition voter base skews old.

Ultimately, however, it has been the activism of Left figures within Labor ranks that has driven the biggest shift in community sentiment, both by forcing the pace of Parliamentary debate (until 2011, the Greens had been the sole party advocating for the issue) and by getting voters to think about the issue. The result has been that a large part of major sections of the electorate — men and Labor voters — have changed their position on the issue, to the point where opposition to same-sex marriage may soon no longer be a mainstream sentiment.