Ohio has adopted a marrriage amendment. One of the issues that has arisen is whether its "second sentence" would forbid the application of domestic violence laws to unmarried couples. Until now, every court of appeal in Ohio that has considered the issue have said that the amendment does not prohibit application of domestic violence laws to cohabitating couples, but now one has.
Whatever happens in Ohio may not mean much for what might happen in Wisconsin, Our "second sentence" is not the same as Ohio's. In Ohio, the legislature is forbidden to recognize a legal status that "intends to approximate the design, qualities, significance or effect of marriage." In Wisconsin, it would be forbidden to recognize a status that is identical or substantially similar to marriage.
By focusing on the status itself rather than its incidents, the Wisconsin language is arguably more narrow.
But the issue is out there.