As the question of gay marriage flares across the US, pressure has mounted on state legislatures to pass constitutional amendments that define marriage as only between a man and a woman.
In Massachusetts, the only state where the court has already mandated same-sex marriage, the deliberations have a particular urgency: Lawmakers last week cobbled together a compromise amendment designed to provide an alternative to the court ruling by banning gay marriage but establishing same-sex civil unions with the same legal rights.
To many, it's a compromise - albeit a shaky one that pleases neither side and may ultimately not pass - designed to shelter an institution that has strong religious significance.
But in practice, some legal scholars warn that the compromise could itself pose a threat to religious liberty, by putting state pressure on churches to accept the concept of civil unions to some degree.
The amendment "may do ... more serious and permanent harm than [the court ruling] itself from the standpoint of protecting the religious liberty of individuals, churches, and other religious organizations," a group of experts from Harvard and other law schools told the Massachusetts Catholic Conference, the church's public policy arm.
The scholars' key concern: introducing "civil unions" into the constitutional lexicon. "It gives wide-ranging license to judges to enforce a new social norm on organizations touched by the law," they said. "Precedent from our own history and that of other nations suggests that religious institutions could even be at risk of losing tax-exempt status, academic accreditation, and media licenses, and could face charges of violating human rights codes or hate speech laws."
Some experts express similar concerns, while others dismiss them as without merit, given constitutional guarantees of religious liberty.
John Witte, professor at Emory University Law School in Atlanta, sees the possibility of an eventual collision between religious liberty and sexual liberty norms, with religious bodies finding it "much more difficult to opt out of recognizing a constitutionally mandated form of alternative union." Eventually, gay couples might also seek "protection against church bodies in employment or enrollment decisions, in clerical appointment decisions, associational decisions with schools, charities, etc.," he adds.
There is wide agreement that a minister, priest, or rabbi has the discretion to decide whom they will marry, and cannot be forced to perform any service.
"Many religions won't perform interfaith marriages," says Erwin Chemerinsky, a law professor at the University of Southern California. "The law would never force anyone to perform either a civil union or same-sex marriage ... All the constitution would say is that the right to have civil unions is protected in the state."
At the same time, some say the debate could raise questions about whether it's appropriate for the clergy to continue to act as agents of the state in solemnizing marriages ("Under the authority vested in me..."). They could be in a difficult posture to say they can do that but can't act as agents of the state in performing civil unions, Dr. Witte suggests.
Some experts are discussing a possible future legal arrangement that would leave marriage to religion and have the state provide contracts for various other forms of intimate association. Witte says this is being contemplated in Canada, and is the current situation in France.
Bill Duncan, visiting law professor at Brigham Young University in Provo, Utah, sees other scenarios where a problem could arise. "A church itself may not be required to give benefits, but other church operations - charities, bookstores, parachurch groups - might be asked to."
Dr. Chemerinsky insists otherwise. "I cannot imagine any circumstance in which the government would force, coerce, pressure religious entities to recognize same-sex marriages or civil unions," he says.
Proponents of gay marriage have taken pains to distinguish between civil marriage and religious marriage. They are pressing for civil rights, they say, which will not interfere with the right of religious bodies to follow their own teachings, as Catholics do on divorce. Of course, that doesn't preclude groups in churches from pressing for change from within.
"We've come a long way in a short time," says State Sen. Brian A. Joyce (D) of Milton, who opposes a ban on gay marriage. "A few years ago it was controversial to consider domestic partner benefits for state employees; several months ago, civil unions were quite controversial. Now the battle is between same-sex couples having the word 'marriage' used or not."
Massachusetts lawmakers meet again on March 29 to take a final vote on the proposed amendment. State law requires that they approve it again next year, to set the stage for a public referendum in 2006.
With the court's May 17 deadline to allow gay marriage looming, state officials are under tremendous pressure to act.