Over the past decade, we have said repeatedly that redefining marriage as something other than the union of one man to one woman paves the way for legalizing polygamy and other relationships as “marriage.” Same-sex marriage proponents have been quick to dismiss those concerns. Polygamy supporters, however, have not.

In an op-ed appearing in the Chicago Tribune last month, Dennis Byrne pointed out that supporters of polygamy and polyamory are celebrating the latest efforts to redefine marriage in America, because they know it paves the way for their form of “marriage” to be accepted as well.

U.S. News and World Report¬†published a quote from polygamy-supporter Anita Wagner Illig in June, saying, “A favorable outcome for marriage equality is a favorable outcome for multi-partner marriage, because the opposition cannot argue lack of precedent for legalizing marriage for other forms of non-traditional relationships.” She also said, “We polyamorists are grateful to our [gay and lesbian] brothers and sisters for blazing the marriage equality trail.”

If same-sex marriage activists do not see themselves setting the stage for polygamy in America, it seems the polygamists certainly do.

As Dennis Byrne points out,

“To be consistent, same-sex marriage proponents now are obliged to push for equality in these other kinds of marriages with the same passion, energy and resources that they campaigned for their own cause. Or will they try to deny polyamorists their equal rights by arguing that two-person marriages are special?”

The next time you hear someone use the phrase “marriage equality” to describe same-sex marriage, you may want to ask them what that term actually means. If you think about it, there’s no logical way “marriage equality” can stop at same-sex marriage–and that’s exactly what polygamists are counting on.