Gay marriage not the electoral silver bullet everyone thinks it will be

'If Malcolm Turnbull just pitches to the middle and ignores the Liberal Party right, he can win the next election,' goes the familiar call from mainstream political journalists. This notion is premised on the belief that appealing to a conservative constituency is stopping the Liberal Party from being competitive in Labor electorates and that, to be a successful Prime Minister, Malcolm Turnbull must dispense with the perceived minority conservative interest and govern for the majority. I believe this argument to be half-baked.

For starters, single issue voters are largely irrelevant on a national stage. There are probably voters who do consider the introduction of gay marriage to be a vote changing issue for them but, quite often, they are in electorates where the sitting MP supports gay marriage and, if not, there is not enough of them to make a dramatic change in the vote. MP's are pragmatic and it is not incidental that the spike in support for gay marriage amongst MP's who have previously been against it, has often come as a result of pressure from their electorate.

Likewise, just how many votes are there to be gained in an already crowded marketplace? Currently, voters who consider same-sex marriage to be their number one priority have Labor, the Greens, the Australian Sex Party and the Liberal Democrats to choose from as well as countless others. Just how many votes would be won if the Liberal Party changed their stance on gay marriage when many other parties have occupied this space for years and have done so with more authenticity? Conversely, the anti-gay marriage space is a less tapped market with One Nation and Family First (now Australian Conservatives) unable to capitalise on their stance against gay marriage because of the Coalition's historic dominance of this marketplace.

This brings me to my next point. Of those voters in favour of gay marriage who consider it to be a vote changer, how many of them are naturally receptive to the Coalition's traditional messages of reduced government spending, low taxes, support for family values, patriotism and strong border protection? There are undoubtedly Liberal voters who are in favour of same-sex marriage but, following on from the previous point, how many current Labor or Greens voters are just raring to vote for some low taxes and border protection just as soon as the Coalition changes its stance on gay marriage?

With this in mind, broader existential questions about the Liberal Party must be considered. I'm not about to add to the wealth of literature on the Liberal Party but, for the purpose of my argument, let me briefly provide my analysis of what I see as the contemporary Liberal Party and who their constituency is.

The Liberal Party under Robert Menzies was the party of the middle class, but under John Howard it became revitalised as the party of working-class aspirationalism through his combination of economic liberalism and social conservatism. Howard excelled by targeting working-class outer-suburban and regional seats by staying grounded and ignoring the concerns of the urbane political class.

Now that isn't to suggest that support for gay marriage is confined to that class but, given the aforementioned points about the limited potential votes gained, would it be worth it to risk alienating those outside the political class when their interests are essential to the success of the Liberal government?

A persistent myth is that it's the so-called centre which are slipping away from Malcolm Turnbull, in actuality it is the outer suburban and regional seats which Turnbull needs to hold in order to retain government, which lean towards social conservatism. In fact, of the six most marginal Coalition seats, three of them are in Queensland- Capricornia, Flynn and Forde. Of those, Flynn is (according to ABC Vote Compass) the third most conservative seat in Australia (behind Maranoa and Kennedy), Capricornia is the fourth and Forde is the eleventh. The other three - Gilmore (New South Wales), Robertson (New South Wales) and Chisholm (Victoria) – are placed towards the middle of the vote compass. This means that, although there might be a small majority of constituents in these electorates who favour gay marriage over those who don't, the issue is unlikely to change the outcome of who holds the seat.

With a one-seat majority, Turnbull can't afford to lose a single seat. But it's worth noting that in seats where support for gay marriage is high, seats like North Sydney (held by Trent Zimmerman who is pushing for the Coalition to support same-sex) Kooyong (held by Josh Frydenberg), Higgins (held by Kelly O'Dwyer) and Turnbull's own Wentworth, are held comfortably by the Coalition.

This throws a spanner in the works to the perceived wisdom of Coalition strategist Mark Textor that, to win, the Coalition needs to put the interests of its socially conservative base second and reach out to the 'middle'. Contrary to the mainstream narrative, the battlelines of Australian politics are not fought in socially-liberal-but-economically-conservative constituencies, but in outer suburbs and regions.

Broadly speaking, these constituencies are more interventionist on economic issues (leaning towards Labor) and conservative on social issues (leaning towards the Coalition). Short of the Liberal Party changing its philosophy to become the economic interventionist party of Australian politics (after the last budget maybe I shouldn't speak so soon), it is socially conservative policies that are going to make the Coalition more competitive in those battleground electorates.

There are some who might argue that remaking the Coalition into a socially progressive party, could mean that all bets are off, with the Liberal Party more competitive in seats they were previously uncompetitive. To that I would say, they would have a long-way to climb with the Liberal Party coming third (behind the Greens) in three of the top five most left-leaning electorates in Australia (which are most likely to prioritise gay marriage as a vote-changing issue)- Batman, Wills and Dennison- while placing a distant second in two- Grayndler and Gellibrand.

Even if a change in Coalition policy around same-sex marriage delivered an extra million votes nationally, that would be inconsequential on the election outcome if those votes were concentrated in seats where Labor is outpolling the Coalition two-to-one (which are the seats where support for gay marriage is at its highest). Conversely, if the Coalition were to bleed a few thousand votes to One Nation over its newfound support for gay marriage, this could mean the difference between holding and not holding marginal seats in Queensland. A loss in even a few of these marginal Queensland seats would cost the Coalition government its majority.

In short, arguments for same-sex marriage are not to be discounted on philosophical principle. But the notion that there are seats to be won for the Coalition through breaking an election promise and introducing gay marriage in the so-called 'national interest' are unfounded. That isn't to categorically dismiss arguments that the Liberal Party needs to change. Institutions must change and adapt to changing times, yet successful ones do so whilst being fully conscious of their supporters and what their brand means to them. The prospect of the Coalition breaking an election promise and introducing gay marriage offers tangible risk for negligible reward.