This week, the highest court of Massachusetts ruled that gay couples have the right to marry under the state's constitution and it ordered the state legislature to make same-sex marriages possible within 180 days.

This unprecedented step was denounced by US president George W. Bush, who vowed to "do what is legally necessary to defend the sanctity of marriage".

He said, "Marriage is a sacred institution between a man and a woman. Today's decision of the Massachusetts Supreme Judicial Court violates this important principle."

A Pew Forum poll revealed that opposition to same-sex marriage has risen from 53 to 59 percent since the US Supreme Court issued a ruling overturning a Texas sodomy law which said that homosexuals, like heterosexuals have the right to "seek autonomy" in their relationships.

It cited "personal decisions relating to marriage" as an important area of personal autonomy. It also held that even if the public opposes "a particular practice as immoral is not a sufficient reason for upholding a law prohibiting that practice."

Morality is not the basis of law?

That is a radical notion concocted by a handful of Supreme Court judges. Massachusetts also rejected the idea, held for thousands of years of human history, that marriage is the union of man and woman which "furthers the legitimate state purpose of ensuring, promoting and supporting an optimal social structure for the bearing and raising of children," as one dissenting justice put it.

What should be done now? "The courts have tossed a political grenade into the legislature, and they have six months to put the pins back in," said Tony Perkins, president of the Family Research Council.

"What they can do is pass a constitutional amendment that says marriage is between a man and woman. We would then have a true constitutional crisis. Will the court extend its stay until voters have had an opportunity to vote and ratify it?"

Probably not, since the court allowed the legislature only six months to act, and the soonest a constitutional amendment could be passed is 2006, after it had been approved by two successive sessions of the legislature, and voted on by the public.

Governor Mitt Romney favours that approach combined with civil unions for gays like that of Vermont. But the Court could order same sex marriages to be approved. Massachusetts would then probably begin to approve gay marriages.

If so, hundreds or thousands of gay couples across America will go to Massachusetts to get married, return home and file law suits demanding their own states recognise their marriages.

Given the US Supreme Court's expansive ruling in the Texas sodomy case, it would likely support legalising gay marriage. The fact that a cabal of judges would be forcing such a major change on a public whose elected representatives would not support it ? appears to many conservatives to be "judicial tyranny."

This prospect has galvanised conservative groups to fight for a Federal Marriage Amendment (FMA) that would block both state and federal court action to rewrite marriage law, as Massachusetts has done.

There are 100 House sponsors of FMA and Senate Majority Leader Bill Frist and other Republicans favour it, though no bill is in the Senate. Problem is, passage would require a two-thirds vote in both Houses of Congress and in three-quarters of state legislatures. Very few Democrats in either House support FMA.

That will change as "lawsuits export this issue to other states," says Matt Daniels, whose Alliance for Marriage drafted FMA. On the other hand, some conservative groups are unhappy with the FMA that would do nothing about civil unions, and are trying to make the Senate bill block them.

If they succeed, passage will be even more difficult since there is growing support for civil unions. Indiana Rep. John Hostettler has a better idea. He says, "The nation's founders never intended for the judiciary to be the most powerful branch of government.

Article III, Section 2 of the Constitution gives the Supreme Court jurisdiction in most cases 'with such exceptions and under such regulations as the Congress shall make.'" Congress has already approved a Defense of Marriage Act (DOMA) signed by president Bill Clinton in 1996, stating that marriage is between a man and a woman. Hostettler proposes an amendment which "would strip jurisdiction for DOMA from the US Supreme Court.

"The time is ripe for dismantling the altar of judicial supremacy," he asserts. That bill requires only 51 percent of the House and Senate to approve it and no state legislative approval, a vastly easier task than passing a Constitutional Amendment.