As you may already know, the Wisconsin Supreme Court has agreed to hear a case against the Wisconsin anti-marriage amendment, which voters passed in 2006. The amendment bars the legislature from expanding the legal definition of marriage to apply to same-sex couples, and also blocks it from creating any legal status that is substantially similar to marriage, whether for gay or straight couples.
The plaintiff is arguing that the way in which voters were asked to weigh in on the amendment violates state law. That's because the law allows only one issue to be covered in each constitutional amendment. The plaintiff says the amendment covers two separate issues: (1) defining marriage and (2) blocking the legislature from granting certain civil rights to non-married couples. For example, a voter who wanted to define marriage as between one man and one woman, but believed that same-sex couples should be afforded protections through substantially similar civil unions, was not given the option to vote in favor of the first part of the amendment, but against the second.
Alex De Grand, legal writer for the State Bar of Wisconsin, has a concise analysis of the legal issues raised in this case.