One question keeps interrupting the campaign, despite both major parties being against it and most being ambivalent about the whole thing.
Marriage equality came up last month, when Penny Wong was asked why she didn't support it.
It came up last week, when Julia Gillard was asked by a lesbian why she couldn't marry the one she loved.
And this week on Q&A, Vietnam veteran Geoff Thomas asked why Tony Abbott couldn't overcome his prejudices and allow gays to marry - just as he had overcome his prejudices and accepted his gay son.
Ignore it, refuse it, roll your eyes at it, but same-sex marriage is the issue which won't go away, one which comes not from the parties, but from the people.
When the Marriage Act was passed in 1961, legislators didn't bother to define marriage as being between a man and a woman. That didn't happen until 2004, when the Howard government with Labor support inserted this definition: "marriage means the union of a man and a woman to the exclusion of all others, voluntarily entered into for life".
At last count, 44 jurisdictions – including deeply religious Portugal, Spain and Mexico City – disagree. They think secular marriage is wider than that, it's the union of two people.
The first was the Netherlands in 2001, followed by Belgium. Argentina is the most recent, where marriage equality was allowed by the legislature, not by courtroom victories more common in the United States.
There, the Bill of Rights allows judges to strike down prejudicial legislation.
The latest came earlier this month, when a federal court judge in San Francisco invalidated Proposition 8, the measure supported by 52 per cent of Californian voters to overturn previous court rulings allowing marriage for all.
The case – Perry v Schwarzenegger, even though the Governor supports same-sex marriage – is instructive for Australians, not for its legal, bill-of-rights basis but its factual findings.
In a demolition job judgement spanning 136 pages, Judge Vaughn Walker found there was no rational reason for limiting marriage to a man and a woman, not one.
Instead, he found that Proposition 8 converted stigma into law.
“Excluding same-sex couples from marriage is simply not rationally related to a legitimate state interest.”
His decision will almost certainly end up before the Supreme Court, and has been stayed appending an appeal.
If the Supreme Court overrules Walker, the case will become to marriage equality what the 1896 disgraceful ruling upholding segregation in Plessy v Fergusson was to black equality.
If it upholds him, it will become Brown v Board of Education, which finally tore down the separate-but-equal nonsense in 1954.
Walker's decision was noticed in Australia, but mainly by younger gays and lesbians, those under about 40.
For them, marriage is not such a radical idea. For them, it's neither radical to think they may be allowed to wed, or that they may to want to.
In April, a University of Queensland study of about 2000 gay and lesbian Australians found while 78 per cent though gay couples should be able to marry, those who would marry varied widely depending on age. Only a third of those over 60 would, compared to about 60 per cent of those aged between 20 and 39.
There has long been divergent views within the gay community over whether or not to seek the right to marry, with all its baggage, or seek something like civil partnerships in Britain or civil unions in New Zealand, or seek nothing at all.
The pro-marriage lobby now seems dominant, commensurate with more countries allowing gays to wed, and with the trend back towards marriage within their straight friends.
More widely, repeated polls of national opinion have shown not only is equal marriage not a radical proposition but a majority of Australians actually supports it.
When Newspoll asked the question in 2004, more were against same-sex marriage (44 per cent) than in favour of it (38 per cent).
But in a remarkably swift shift, when Galaxy asked the question again in 2007, sentiment had reversed.
In a poll of 1100 people commissioned by the progressive group GetUp!, 57 per cent thought gay couples should be able to wed, with 37 per cent opposed.
When Galaxy again asked 1100 people last year, this time on behalf of a gay marriage lobby group, the shift had solidified to 60 per cent in favour. All age groups under 50 supported it, and even 45 per cent of older Australians did and half of Coalition voters did, too.
Still, it won't happen anytime soon.
Marriage is controlled by the federal parliament, and if a state were to allow gays to wed, the federal law would override it.
That doesn't stop a state allowing civil unions, although NSW Labor allows gays only a register, seemingly scared of being seen to start a union rather than reluctantly recognising one that already exists. (If you must, dear, but don't expect us to like it.)
In the federal parliament, the Liberal Party, controlled by social conservatives, is not going to allow two men to marry.
The Greens, who would, are not going to have sufficient numbers any time soon.
And Labor has repeatedly said no. Having lost its nerve on climate change, it is hardly likely to chance its arm at putting the relationships of a small minority on the same level as everyone else's.
On Q&A, Graham Richardson explained why, when rubbishing criticism of Penny Wong's support for her party's position.
"There are a lot of people in the Labor Party who don't agree with this stuff. At the moment there's nowhere near a majority but there will be," he said. "There will be over time because Penny will work for it and it will get up in the end.
"But give her a break, for God's sake. She's part of a caucus. There's a whole lot of them. She doesn't run the government, she's a part of it. A part of it.
"There's a thing called cabinet solidarity and if she wants to break it she gets nowhere. You'll lose someone who fights for your cause. That, my friends, is dumb. Big time dumb."
Richardson seemed to have little tolerance of the idea that democracy should be more than telling gay and lesbian Australians to sit on their hands, offer no public criticisms, and be confident that fellow travellers inside the Labor tent will fight the good fight and get there. Eventually.
If it is difficult enough to motivate a gay community now to agigtate for the last two steps towards civil equality - marriage and federal anti-discrimination laws - it's almost impossible to motivate straights.
Much of the straight support is dinner-party support, the kind you give when you're in favour of it but aren't affected by the outcome.
You might nod furiously around the mahogany dinner table – bang it, even - but you're hardly going to march in the streets for the right of someone else to make you buy them a wedding present.
Most, I would guess, are content to wait until politicians decide it's politically safe enough to do.
Those who are prepared fight for it are a tiny minority, and they tend to live in safe inner-city seats, like Tanya Plibersek's Sydney or what was Lindsay Tanner's Melbourne.
Those who deeply hate it are a minority too, but they form a greater presence in the marginal seats on the city fringes.
The last major groups against gay marriage are the religious and those who covet their support. Marginal seats like Lindsay and Hughes in NSW, and Dickson and Bonner in Queensland, have significantly higher percentages of believers. Census records show in Lindsay, for instance, 75 per cent are Christian, while in Sydney – which covers inner-city suburbs like Darlinghurst and Ultimo – just 40 per cent are.
As demographer Bernard Salt wrote in The Australian in March: "The lesson for politicians is clear. If you want to align yourself with swinging electorates on the edge of town, then convert to Catholicism."
Often, political reform depends not on the power of your argument, but the location of your constituency of support.
The arguments in favour of fair marriage for all are well-traversed, conservative and powerful. There is no rational reason against it, only religion.
Legally, it is an easy, quick legislative fix of changing the definition in the Marriage Act, and some minor consequential amendments.
Politically, it is not even if a majority supports it.
Marriage equality is not the victim of the tyranny of the majority.
It is a victim of the tyranny of a powerful minority living in important electorates, a tyranny assisted by the ambivalence of some who would benefit from it.
In a country with no bill of rights, the courts cannot uphold human dignity in the face of such prejudice.
It is left to a few to win over a majority of such size the cowards in the supposedly progressive party will let it happen.
Until then, gay couples wanting to marry will have to elope from the home of Mardi Gras to modern Gretna Greens like Canada or Conneticut, Sweden or Spain, or those historic bastions of liberal thought like South Africa, Mexico City and Argentina.