TALLAHASSEE — The fate of the most emotionally charged issue on Florida's November ballot could hinge on a question of economics.
Would constitutionally banning gay marriage threaten benefits for thousands of Floridians — gay, straight or even siblings living together — who depend on their domestic partnership to pay for health care?
Amendment 2 supporters say no way. Amendment 2 opponents say absolutely.
Passage of similarly worded gay marriage bans in other states have thrust domestic partner benefits into courtrooms. So far, one state's supreme court has ruled that the ban prevented public employers from granting domestic partner benefits, although affected employers created new legal avenues so that no employee lost benefits.
Florida already bans gay marriage by state law. But supporters say they need the constitutional ban to prevent legislators from changing the law or judges from overturning the law, as happened in California this year.
Twenty-six states bar same-sex marriage in their state constitutions. Florida voters join those in California and Arizona considering a ban on Nov. 4.
In Florida, the measure needs 60 percent approval to pass, a threshold recent polls suggest is possible.
Florida's Amendment 2 defines marriage as "the legal union of only one man and one woman as husband and wife."
But it's the second clause of Amendment 2 that could cause problems: "no other legal union that is treated as marriage or the substantial equivalent shall be valid or recognized."
Similar wording prompted Arizona voters in 2006 to reject a constitutional gay marriage ban — the first and only such failure nationwide — because of fears it would block domestic partner benefits.
A Nov. 4 measure in Arizona dropped the part that might prevent local governments from recognizing "legal status for unmarried persons."
Michigan passed a 2004 ban that resembles Florida's wording. In May, Michigan's Supreme Court became the first and only nationwide to decide that the ban prevents local governments, schools and universities from offering partner benefits, if the benefits calls attention to same-sex relationships.
Michigan school districts and universities found creative ways around the ruling, however, by loosening up the definition of domestic partner.
"Nobody has lost health care benefits, that I'm aware of," said Jay Kaplan, an attorney with the Michigan American Civil Liberties Union.
At least 75 public and private employers in Florida, including the Times, offer domestic partner benefits, according to the Human Rights Campaign, a nonprofit organization that lobbies governments on gay-rights issues. Those employers include nine of the state's 28 community colleges, as well as the University of Florida, Florida International University and the private University of Miami.
Private employers' benefit plans wouldn't be affected by a ban, predicted the campaign attorney Lara Schwartz. But for public employers, it's unclear.
State economists, who are required to assess the financial implications of ballot measures, said the measure could have an impact on local government domestic partner benefits. But they didn't know what the financial repercussions would be.
Most Florida insurers and public employers — including Humana, United Health Care and the University of Florida — said they're unsure of Amendment 2's affect or believe a court will ultimately decide.
But the head of the state's largest health insurer, Blue Cross and Blue Shield of Florida, was pretty blunt in her assessment.
"It's going to have a major impact on our ability to provide benefits for domestic partners, and we're opposed to anything that gets in the way of providing benefits," said Randy Kammer, an attorney and vice president for regulatory affairs and public policy.
Blue Cross and Blue Shield offers domestic partner benefits to its own employees, and administers many public employee health plans. Kammer said the insurer opposes the amendment, although it's not spending money to actively fight it.
The head of Florida4Marriage, the group that sponsored the ballot measure, disagrees with the insurer.
John Stemberger said the ballot's language was crafted to avoid affecting domestic partner benefits. He said domestic partnerships are not the "substantial equivalent" of marriage, so they'd be unimpeded.
"It's completely wrong," Stemberger said about the claim that domestic partner benefits would be threatened.
But Florida Red and Blue, the group opposing the ballot initiative, said it believes that domestic partner benefits are at stake.
"Is a domestic partnership treated as marriage? Who knows?" said Derek Newton, the group's campaign manager. "The certainty here is, it's going to be a legal nightmare, and it's going to be up to a judge to determine whether or not people are going to lose benefits as a result of this amendment."
Newton said he's sure that somebody will attack domestic partner benefits, because that has happened in other states after constitutional amendments passed.
The Florida Family Association started laying the groundwork earlier this year to challenge same-sex partner benefits offered to Tampa city employees, asking for public records about the policy's legality and cost.
"It would be unfortunate if this amendment did away with domestic partnership benefits at a time when we should be expanding them in every city, county and university across the country," Tampa Mayor Pam Iorio said.
Times Staff Writer Janet Zink contributed to this report.