Does the Commonwealth Marriage Act inadvertently facilitate gay marriage?

"Marriage is a wonderful institution, but who wants to live in an institution? " In contemporary Australia the answer to Groucho Marx's famous quip is “An ever-increasing  number of same-sex couples”.

Dozens of Australian same-sex couples have already married in Canada. That number will increase exponentially as more countries allow gay unions to be officially solemnised.

To guard against any changes to Australian laws, last year the Howard Government amended the Commonwealth Marriage Act to ban the recognition of foreign gay marriages by Australian courts and to spell-out, in a way the law had previously failed to do, that marriage in Australian law is between a man and a woman.

Many people, gay and straight , saw this discriminatory amendment as the end of the issue. But by closing one door to same-sex marriage the Federal Government inadvertently opened another.

It's been half a century since Australian states exercised the constitutional power they share with the Federal Government to enact marriage laws. Most people have forgotten this power even exists. It can't validly be used if state marriage law in any way duplicates or conflicts with its federal equivalent. The Australian Constitution ensures that in these circumstances federal law always has precedence.

But because last year's marriage amendment made crystal clear that federal marriage law deals only with different-sex marriage, the states are now free to pass constitutionally valid laws for same-sex marriage.

Constitutional law expert, Professor George Williams, has confirmed this tectonic constitutional shift. He believes state same-sex marriage laws would operate in a different and mutually exclusive "field" to federal marriage laws and would likely be upheld by the High Court.  "An analogy can be drawn with the approach taken by the High Court to whether a federal industrial award overrides a state award. The court has held that, where a federal award makes no provision on a particular matter, a state award may be able to operate on that matter without being overridden under section 109."

Seizing on the mandate the states now have to pursue same-sex marriage, the Tasmanian Greens have introduced relevant legislation to the State Parliament.

According to Greens Justice spokesperson, Nick McKim,"The time has come to begin a mature debate on the issue of same sex marriage, which I hope will lead to the removal of one of the final bastions of discrimination faced by same sex couples".

McKim's is an honest admission that community debate must  precede the recognition of same-sex marriages by the states. The Howard Government cut that debate short before it really even began. Now the country has a second chance to hear and weigh up the case for change.

What it will hear is that marriage reform is about treating everyone equally under the law, as well as bringing the benefits of marriage to same-sex couples and the children in their care. It will hear that the right to marry the partner of one's choice is a key marker of adulthood and citizenship and the denial of this right stigmatises same-sex couples and their families as second-rate and dysfunctional.

It will hear that marriage has changed dramatically through the ages. That what defines it in today's democratic, secular society is not religion or procreation but mutual love and that if marriage fails to continue to adapt to social change, it will grow increasingly irrelevant and wither away.

But most of all it will hear that same-sex couples want to marry for all the same reasons as their heterosexual counterparts: Chief amongst them a couple's desire for an official and public acknowledgement of their mutual love and commitment.

Back when Groucho Marx summed up the reservations many heterosexuals had about "the institution" of matrimony, gay marriage seemed bizarre, not least to those homosexuals who led the 20th century's march toward individual fulfilment.

But times change. If freedom was the catch cry then, today it is belonging. It is the search for home in a world of alienation and social disconnection that many homosexuals now lead. And the banner under which they march is the right to marry.