A couple of weeks back, I commended Sen. John McCain for delivering the commencement address at Jerry Falwell’s Liberty University in Virginia without pandering, without compromising his principles and without behaving like the medieval German emperor who waited barefoot in the snow at Canossa in penance for having offended the Pope.

In his radio message on Saturday, endorsing the Federal Marriage Amendment, President Bush did the opposite. To secure the support of the religious right for Republican candidates this fall, he delivered what was perhaps the most abject, the most craven and the most disingenuous public statement by a chief executive since Bill Clinton lied with a straight face about his relations with Monica Lewinsky.

The President said this: “Today I call upon the Congress to promptly pass, and to send to the states for ratification, an amendment to our Constitution defining and protecting marriage as a union of man and woman as husband and wife. The amendment should fully protect marriage, while leaving the state legislatures free to make their own choices in defining legal arrangements other than marriage.”

Anyone not familiar with the FMA might assume from what Mr. Bush said that the amendment does nothing more than define marriage as a union between one man and one woman, and leaves the states free to “make their own choices” regarding gay unions and domestic partner benefits.

But in fact the FMA has two parts. First, it says, “Marriage in the United States of America shall consist only of the union of a man and a woman.” And then it goes on to say, in the second part, “Neither this Constitution, nor the constitution of any State, shall be construed to require that marriage or the legal incidents thereof be conferred upon any union other than the union of a man and a woman.”

What, exactly, does the second part mean? If part one of the amendment says that marriage in the U.S. shall consist only of the union of a man and a woman, why is this additional language necessary to accomplish the goal of the amendment?

Nobody really knows at this point. But if the FMA is ratified, it will open -- not a Pandora’s box -- but a veritable steamer trunk full of thorny constitutional questions.

If the FMA were ratified, any state law permitting gays and lesbians to enter into civil unions could be challenged by fundamentalist groups as being invalid under the constitution of that state. The same would apply to state and local laws conferring domestic partner benefits on gay and lesbian public employees.

What then? The second part of the FMA says that no state constitution may be construed to require that the “legal incidents” of marriage be conferred upon non-traditional couples. Does this mean that state courts could not construe their state constitutions to uphold laws permitting civil unions or domestic partner benefits for gays and lesbians? Does it mean that such laws would be presumptively unconstitutional? The amendment doesn’t say.

If state courts did uphold such laws, would the FMA allow opponents of any form of non-heterosexual union to appeal such rulings to the U.S. Supreme Court?

Or suppose that the people of a state amended their constitution to permit gays and lesbians to marry? Would the FMA allow the people who lost the battle over the state amendment to appeal the U.S. Supreme Court to keep the amendment from being put into effect?

At the very least, ratification of the FMA would give rise to endless wrangling over what state legislatures could do to allow non-heterosexual couples to formalize their unions. They would hardly be “free to make their own choices.”

The FMA would deprive the states of their power to regulate marriage – a power they have had since the dawn of the republic – and it would limit the power of state supreme courts to construe their own state constitutions. There was a time when conservatives would have been the first to denounce a federal power grab of this sort.

Mr. Bush ended his radio address with a masterpiece of mendacity:

“Our government should respect every person, and protect the institution of marriage. There is no contradiction between these responsibilities. We should also conduct this difficult debate in a manner worthy of our country, without bitterness or anger.

“In all that lies ahead, let us match strong convictions with kindness and goodwill and decency.”

But the FMA is itself a gross indecency – exceeded only by Mr. Bush’s spineless endorsement of it.