The American Civil Liberties Union of Wisconsin on Monday filed a federal lawsuit seeking to void the state’s ban on same-sex marriage, arguing it violates the U.S. Constitution’s guarantee of equal treatment and denies a basic right to gay couples.

“We expect that this lawsuit will bring the freedom to marry to all Wisconsinites,” Larry Dupuis, legal director of the ACLU of Wisconsin, said at a press conference Monday.

In a statement, state Attorney General J.B. Van Hollen said he plans to defend the amendment, which passed with a 59 percent margin in 2006.

“This constitutional amendment was approved by a large majority of Wisconsin residents,” Van Hollen said. “I believe the amendment is constitutional, and I will vigorously defend it.”

A spokesman for Gov. Scott Walker said the governor was not available to comment Monday. The Associated Press reported Walker was in Texas on a campaign fundraising trip.

The complaint filed in U.S. District Court in Madison requests an immediate halt to enforcement of Wisconsin’s ban on same-sex marriage. The ACLU has launched federal court challenges to similar bans in five other states, said John Knight, an attorney with the national ACLU’s Lesbian Gay Bisexual Transgender Project.

Knight said Wisconsin’s ban is “especially egregious” because it prohibits gay marriage and anything similar, including civil unions, and also makes it a crime for gay couples to go outside Wisconsin to marry under the state’s obscure “marriage evasion” law.

The action was brought on behalf of four couples. Three of the couples — one from Madison, two from Milwaukee — want the state to legally recognize their relationships by allowing them to marry. The fourth couple, from Eau Claire, was married in Minnesota in December and is asking Wisconsin to recognize that union.

Judi Trampf and Katy Heyning of Madison said banning them from marrying after nearly 25 years as a couple is unfair and hurtful.

Both work at UW-Whitewater; Trampf is director of human resources and diversity, and Heyning is dean of the College of Education and Professional Studies.

Trampf recounted an episode in 2002 in which Heyning had a seizure “and my authority to make medical decisions on Katy’s behalf was challenged by the hospital, because we were not married.”

Trampf said even though the couple had been together 10 years at the time, the hospital preferred that Heyning's brother, whom she hadn't lived with since childhood, should make decisions.

Said Heyning: “We love each other, and denying us the freedom to marry just doesn’t seem right.”

The political and legal landscape has changed significantly since Wisconsin passed its same-sex marriage ban. In June, the U.S. Supreme Court struck down the federal Defense of Marriage Act, which banned same-sex couples legally married in their own states from receiving the same federal benefits as heterosexual married couples.

In recent years, 17 states plus the District of Columbia have legalized same-sex marriage through laws, popular referendum or court challenges. In 2013 alone, expansion of marriage to include gay couples became the law in nine states.

Gov. Walker has voiced support for Wisconsin’s gay-marriage ban. He told Bloomberg News in November that the state has a “healthy balance” because while a constitutional amendment limits marriage to heterosexual couples, state laws ban discrimination based on sexual orientation.

Dane County District Attorney Ismael Ozanne, who is running for attorney general, said if he were in the state office,“I would not defend the constitutional amendment because I don’t think there is a good-faith basis to do so.”

Another Democratic candidate for attorney general, Rep. Jon Richards of Milwaukee, also said he would not defend the amendment if elected to the post.

“As Attorney General, it will be my obligation to the citizens of Wisconsin to defend their constitutional rights; rights that I believe are currently being violated for same-sex couples,” Richards said in a statement. “I support marriage equality, and under my leadership, the Department of Justice will be an ally of those seeking equality for all individuals in Wisconsin.”

A message left for the announced Republican candidate for attorney general, Waukesha County District Attorney Brad Schimel, was not immediately returned.

The amendment ratified by voters in 2006 stated, “Only a marriage between one man and one woman shall be valid or recognized as a marriage in this state. A legal status identical or substantially similar to that of marriage for unmarried individuals shall not be valid or recognized in this state.”

Three years later, in 2009, the state Legislature passed a domestic-partner law signed by Democratic Gov. Jim Doyle that allowed unmarried couples to register to qualify for some benefits normally afforded only to spouses.

Wisconsin Family Action sued the state in 2010, saying that law creates a “legal status … substantially similar to that of marriage for unmarried individuals” in violation of the state Constitution. The case is pending before the state Supreme Court.

Julaine Appling, president of Wisconsin Family Action, said Monday’s challenge, coming on the heels of the June decision striking down the federal Defense of Marriage Act, is not a surprise.

“Our organization will continue to do everything that we can in the Legislature, in the culture and in the courts to defend and preserve traditional marriage,” she said.

Fair Wisconsin president Katie Belanger, whose organization is defending the Wisconsin Domestic Partnership Registry in court, said the ACLU’s lawsuit “alone cannot accomplish the transformative change we seek.”

“There must be an effective statewide grassroots movement that prevents backlash and ensures the public is ready for our victory,” Belanger said in a statement.

The complaint filed Monday recounts numerous instances in which the four plaintiff couples were denied equal treatment compared to heterosexual married couples: qualifying for family memberships at a health club, tax breaks and discounted group health insurance, family leave time, and the ability to make life-or-death decisions if a partner becomes gravely ill.

In 2011, plaintiff Garth Wangemann had surgery. Due to complications, he was placed in a coma, from which he emerged four weeks later.

During that time, his longtime partner, Roy Badger, an editor at UW-Milwaukee, wanted to continue life support, but Wangemann’s father wanted to discontinue it.

Badger was able to make the final call only because Wangemann, who works in customer service, had granted his partner the power of attorney for health care.

“If we had been legally married, no one would have even questioned Roy’s involvement as my spouse,” Wangemann said of his partner of 37 years.

Milwaukee residents Charvonne Kemp, an accountant, and Marie Carlson, who works in manufacturing, have raised two sons together during their nearly eight years as a couple. Kemp said they contemplated going to Canada, Illinois or Massachusetts to get married, but “I have an issue with breaking the law, in general.”

Added Carlson: “We intend to fight as far as we have to go, until there’s the day that I can walk down the aisle with my partner and my love and marry her, legally.”

Editor's note: This story has been corrected to accurately reflect Katy Heyning's relationship with her brother.

Get local news delivered to your inbox!

* I understand and agree that registration on or use of this site constitutes agreement to its user agreement and privacy policy.

Listen up!

Sign up for our Podcasts email!

* I understand and agree that registration on or use of this site constitutes agreement to its user agreement and privacy policy.