In courtrooms and state capitols nationwide, opponents and supporters of gay marriage (search) have embarked on a collision course, pursuing lawsuits and legislation so deeply at odds that prolonged legal chaos is likely.
One plausible result: a nation divided, at least briefly, between a handful of states recognizing gay marriage and a majority which do not.
The most clear-cut option for averting such chaos is a federal constitutional amendment (search) banning gay marriage. However, despite support from President Bush, the amendment is given little chance of winning the needed two-thirds support in both the House and Senate this year.
Without it, experts say, the rival sides are likely to litigate so relentlessly that the U.S. Supreme Court will eventually be compelled to intercede and clarify whether a legal same-sex union in one state must be recognized in other states.
"It's going to be complicated for many years -- we're going to have some free-marriages states, and some that are not," said Matt Foreman, executive director of the National Gay and Lesbian Task Force (search).
"This is not a new situation in our country," Foreman added. "We have had a hodgepodge of laws on different social issues. Invariably, we come to widespread consensus, and that's going to happen to this issue."
For now, though, consensus seems distant as two contrasting legal offensives take shape.
On one hand, courts in five relatively liberal states -- California, New Jersey, New York, Oregon and Washington -- are being asked to consider whether same-sex marriages should be allowed.
In each of these states, local officials have recently performed gay marriages. Gay-rights supporters predict the supreme courts in at least a couple of the states will join Massachusetts' Supreme Judicial Court in authorizing such marriages.
Meanwhile, legislators in many states are moving to amend their constitutions to toughen existing bans on gay marriage and explicitly deny recognition to same-sex unions forged elsewhere.
Four states -- Alaska, Hawaii, Nebraska and Nevada -- already have such constitutional amendments. Similar measures are either certain or likely to go before voters in several other states in November or thereafter, including Alabama, Arkansas, Mississippi, Utah and Wisconsin.
In 10 other legislatures, proposed constitutional amendments are pending -- their fate not yet certain.
Matt Daniels, who as head of the Alliance for Marriage (search) helped draft the proposed federal constitutional amendment, sees the developments in state legislatures as proof of strong grass-roots opposition to gay marriage.
"As the courts push the envelope, public opinion moves in our direction," he said. "It's a great national referendum ... on whether we as a society are going to send a message through our laws that there's something uniquely special about marriage between a man and a woman."
However, Daniels is convinced that without an amendment putting that definition in the U.S. Constitution, the courts will eventually strike down state laws banning gay marriage, as well as the federal Defense of Marriage Act (search). That measure, signed by President Clinton in 1996, allows states to refuse to honor same-sex unions performed elsewhere, and denies federal recognition to such unions.
Daniels said the proposed federal amendment, if it did clear Congress, would easily win the required ratification by at least 38 state legislatures.
He acknowledged that the measure may have difficulty getting two-thirds backing in the current Senate, where few Democrats support it. But he predicted that pressure on politicians to approve the amendment will increase, once gay couples married in Massachusetts or elsewhere successfully sue to have their marriage honored in other states.
"When the lawsuits start to export what happens in Massachusetts, you will have a political powder keg for politicians who refuse to pay heed to public opinion," Daniels said. "This will change the political landscape."
William Reppy, a Duke University law professor, agreed that a challenge to the non-recognition of gay marriages across state lines will be critical -- perhaps what ultimately decides the issue.
"There will be a split of authority -- one state court will say it's valid, another will say it isn't," Reppy predicted. "Then the U.S. Supreme Court would have their hand forced, and hear the case. They don't let splits of authority run rampant around the country for very long."