Wisconsin Gov. Scott Walker was sued Monday by four same-sex couples seeking the right to marry and overturn a law that threatens imprisonment to those who seek legal recognition in other states.
The complaint, filed in federal court in Madison by the American Civil Liberties Union, is the latest by advocates seeking to expand recognition for gay couples beyond the 17 states where such marriages are allowed.
"It is our hope that Wisconsin will soon join the other 17 states in granting the freedom to marry," said John Knight, an attorney with the ACLU Lesbian Gay Bisexual and Transgender Project.
Advocates of gay marriage moved the fight for recognition to the state level following the U.S. Supreme Court's decision in June that left standing an order ending California's ban on same-sex marriage.
The court didn't say whether similar state laws should also be struck down, leaving lower courts to grapple with that issue.
New Mexico was barred by its highest court on Dec. 19 from denying same-sex couples the right to marry.
Last month, Virginia Attorney General Mark Herring said he would seek to overturn his state's ban. He is the fourth state attorney general to refuse to defend such a law.
Wisconsin's ban violates the U.S. Constitution's guarantees of due process and equal protection under the law, according to the complaint.
The law sends a message that lesbians, gay men, and their children are "second-class citizens," the ACLU said.
"The only way for Wisconsin couples to get the federal protections that come with marriage is for them to go out of state to marry," the ACLU said. "But Wisconsin law says that may be a crime punishable by nine months in jail and a $10,000 fine."
The statute makes it a criminal offense to go outside the state to "contract a marriage prohibited under the laws of Wisconsin."