Michigan has gone farthest, prohibiting cities, universities and other public employers from offering benefits to same-sex partners. In all, 27 states have passed constitutional amendments defining marriage as the legally sanctioned union of a man and a woman.
Kalamazoo and the Ann Arbor school district have notified employees that they will end domestic partners' benefits. An appeal is before the state Supreme Court.
Kentucky Attorney General Gregory Stumbo ruled this month that the University of Kentucky and the University of Louisville may not offer benefits to domestic partners, gay or straight.
A U.S. appeals court last year upheld Nebraska's amendment barring government employers from granting benefits, including health insurance, to same-sex couples. It didn't address benefits for unmarried heterosexual couples.
Ohio state Rep. Tom Brinkman, a Republican, has filed a lawsuit to bar Miami University of Ohio from offering benefits to same-sex partners of employees.
"We're in kind of a giant race, a historic race, with all these court cases," says Matt Daniels, president of Alliance for Marriage, which lobbies for a marriage amendment to the U.S. Constitution. "When the dust settles, we'll have a national standard for marriage. What is going on in the states is a dress rehearsal."
Gay-rights activists say they are fighting for families, too...