Michigan's highest court has a 5-2 Republican majority, and the couples could find the court's conservatives will stick to what they see as the plain language of the law.

If those justices interpret the constitutional amendment broadly, it's easy to see why employers and gay workers are nervous. They want to win the underlying case as a matter of principle and not have to fall back on arguing that the same-sex benefit policies are OK as long as they're worded carefully.

Up to 20 public universities, community colleges, school districts and local governments in Michigan have same-sex benefits policies covering at least 375 couples. Universities, which employ most of those affected, argue that not being able to offer the benefits will hurt them when it comes to recruiting faculty and staff.

Many schools filed papers with the Supreme Court saying the appeals court created a "near disastrous" situation by leaving them to guess whether their benefit packages are legal and putting employees "in a continual state of uncertainty and anxiety."

Sixteen of the gay plaintiffs have partners who currently get health benefits. Five others work for the state, which agreed to start offering same-sex benefits in 2004 but won't put them into place until courts clear up the dispute.

The case is National Pride at Work v. Granholm

On the Net:

American Civil Liberties Union of Michigan: http://www.aclumich.org

American Family Association of Michigan: http://www.afamichigan.org

Attorney General Mike Cox: http://www.michigan.gov/ag

Gov. Jennifer Granholm: http://www.michigan.gov/gov

Michigan Supreme Court: http://www.courts.michigan.gov/supremecourt

National Pride at Work: http://www.prideatwork.org