I HAVE yet to come across anyone who was in favour of same-sex marriage changing their mind to be against it. The traffic is all one way.

So the longer Prime Minister Tony Abbott puts off a vote on it the more likely the Australian Parliament will legislate for it.

Delay seems to be his present tactic. The Government can determine the parliamentary agenda and simply not allow time for the Private Members’ Bill sponsored by two Labor and two Coalition MPs to come to a vote.

Presumably, that attitude might change if Abbott concludes that continued opposition will pose a greater threat to his prime ministership through loss of votes in marginal electorates at an election than the threat to his prime ministership through loss of support of MPs who oppose same-sex marriage in the party room.

If the Parliament gets a vote and it passes, the sky will not fall in.

I have been travelling around the US in the past week or so. The US is reeling a little over the US Supreme Court decision that in effect commanded that same-sex marriage be legalised throughout the United States.

But life is still going on.

Part of the shock came because it came from a court decision rather than from an elected legislature.

But the US Congress, unlike our Parliament, has no constitutional power over marriage. 

A lot of the media coverage and views in the street were dominated by partisan expressions in favour or against the decision based on religious and societal views about same-sex couples. They displayed precious little understanding of how the Supreme Court arrived at it decision.

That has often been the reaction to High Court cases in Australia – a concentration on the result rather than how the result was arrived at.

In Australia the reaction to the High Court’s decision to strike down the ACT’s same-sex marriage law was taken as a defeat for same-sex marriage in Australia, yet the reasoning in the case was in fact a major victory for it.

This is because in striking out the ACT law, the High Court held that the Federal Parliament had legislated in an exhaustive way over marriage and so there was no room for any state or territory law on the subject. 

More importantly, though, in getting to that position, it had to decide what the word “marriage” meant in the constitutional provision that gave the Parliament power to make laws “with respect to marriage”. The court gave it a very wide meaning. The result is that Federal Parliament has power to allow or bar marriages between people of the same sex. It could allow or bar polygamous marriage also. It could also set whatever age it sought fit for marriage, and so on.

In short, if the Federal Parliament allows for same-sex marriage, the chances of a successful High Court constitutional challenge are virtually zero.

It would be a straightforward case of the Federal Parliament legislating within is constitutional power.

The position in the US was far more complicated.

Kevin Russell who teaches law at Harvard and appears fairly regularly before the Supreme Court explained some of the history and legal principles at the conference of the Australian Bar Association in Washington this week.

For a long time the court has been divided between originalists, on one hand and judges who say they are enforcing a contemporary or living Constitution, he said. The latter view prevailed in the same-sex marriage case after more than 20 years of jurisprudence.

Hawaii legislated to define marriage as between a man and a woman in 1993. Other states followed.

The during Bill Clinton’s presidency, Congress passed the Defence of Marriage Act, again confining marriage to people of opposite sexes.

Then the legislative and political mood moved the other way. In 2003 Massachusetts passed a law allowing same-sex marriage.

Also in 2003 the Supreme Court held that a Texas law criminalising homosexual acts was contrary to the fourth amendment which affirms the “right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures . . . “.

Similar laws in other states were therefore also invalid.

Then in 2013 a political and legal turning point came when the Clinton Defence of Marriage law was challenged. A same-sex couple legally married in a recognising jurisdiction objected to US federal law not recognising their marriage. 

The Obama administration refused to defend the law, so a public-interest group stood in. The court struck the federal law out on the ground that it would be an affront to the (same-sex recognising) states for the federal government not to recognise their laws.

So some states (about 38) allowed same-sex marriages and others (mainly in the South) specifically banned it. So, last month the Supreme Court was more or less forced to resolve the conflict.

The majority (contemporary constitutionalists) said marriage was a fundamental right. So any state law that excluded one class of people from it offended the 14 th amendment that said no state shall deny to any person within its jurisdiction "the equal protection of the laws".

So that is how a court could apply same-sex marriage throughout the country. It was a matter of states’ rights and individual rights. 

There was some resistance in conservative states, but interestingly other state officials said it was important to uphold the rule of law and did not resist allowing same-sex couples from marrying under state laws and procedures.

In all, whether same-sex marriage is legislated or comes about through court action, the world does not end and more people end their resistance to it.

The US experience shows it is a rights issue. We do not have a Bill of Rights so it will be up to the legislature to grant those rights. Delaying, obstruction or avoiding a decision would be simply letting personal religious views override individual rights.