Four same-sex couples have filed a federal lawsuit challenging Wisconsin's ban on gay marriage.

Carol Schumacher and Virginia Wolf of Eau Claire married in another state but a constitutional amendment approved by voters in 2006 prohibits Wisconsin from recognizing their marriage. Wisconsin law also makes it a crime for gay couples to legally marry in another state.

Plaintiffs also include Roy Badger and Garth Wangemann of Milwaukee, who have been together 37 years. Badger's power of attorney was challenged three years ago when Wangemann fell into a medically induced coma for nearly a month and Wangemann's father wanted to have his son taken off life support.

“What upset me the most was that after all of our time together, our relationship was not fully recognized by my family and there was a real danger that my wish to give Roy the ability to make decisions about my care could be stripped away,” Wangemann said in a statement. “Thankfully, our wishes held in this case. But without the protections that come with marriage, the consequences can literally be a matter of life or death.”

Other plaintiffs in the case are Charvonne Kemp and Marie Carlson of Milwaukee and Judi Trampf and Katy Heyning of Madison.

The couples, who are represented by the American Civil Liberties Union (ACLU), filed their case in federal court in Madison on Monday morning.

John Knight, staff attorney with the ACLU Lesbian Gay Bisexual and Transgender Project, said: “More and more Americans over the past few years accept the idea that same-sex couples and their families shouldn't be treated differently than other families. It is our hope that Wisconsin will soon join the 17 states in granting the freedom to marry.”