"This case could be the one that overturns everything nationwide. We felt that being in the same district, it's kind of our obligation to do this." —Jeff Allen

DENVER — Colorado same-sex marriage supporters rallied outside the federal courthouse in downtown Denver on the eve of Utah's defense of its law banning gay and lesbian unions.

Support Marriage Equality in Colorado put on the event to support the three Utah couples whose case will be heard by the 10th Circuit Court of Appeals on Thursday. The group says the issue matters to Coloradans because the state is part of the 10th Circuit.

"We just wanted to make sure that we showed the community and our state that we support the families. We wanted to let everyone know why marriage matters to our families," said Jeff Allen, who founded the organization.

About 250 people attended the rally on the steps of the Byron White Federal Courthouse where lawyers for the Utah couples and the state will argue before a three-judge panel Thursday.

The outcome could have implications in Colorado, which passed a state constitutional ban on same-sex marriage in 2006. It is among six states that make up the 10th Circuit along with Oklahoma, Kansas, New Mexico, Wyoming and Utah.

"This case could be the one that overturns everything nationwide," Allen said. "We felt that being in the same district, it's kind of our obligation to do this."

The Utah case is the first to reach a federal appellate court since the U.S. Supreme Court struck down part of the Defense of Marriage Act in U.S. v. Windsor last summer. That case figures to play a prominent role in Thursday's oral arguments.

A year ago last month, Derek Kitchen and Moudi Sbeity, Laurie Wood and Kody Partridge, and Karen Archer and Kate Call challenged Utah's law against same-sex marriage in federal court.

U.S. District Judge Robert J. Shelby's ruling last December upended Utah's voter-approved Amendment 3 defining marriage as between a man and a woman. He found the law violates the due process and equal protection clauses of the 14th Amendment.

Utah appealed Shelby's decision and obtained a stay from the Supreme Court but not before about 1,300 same-sex couples were married in Utah. The 10th Circuit will decide whether to affirm or reverse his ruling.

In Windsor, the high court struck down the section of DOMA that defines marriage as between a man and a woman for purposes of federal law, ruling that the government must give the same benefits to gay married couples as it does to heterosexual married couples.

Utah contends Windsor also recognizes the state's authority to define and regulate marriage. The plaintiffs argue that any state definition of marriage must be constitutional.

75 comments on this story

Since the high court ruling on DOMA, eight federal judges, including Shelby, have struck down state bans on gay marriage or on the recognition of same-sex marriage from other states. Those states are Michigan, Nevada, Ohio, Oklahoma, Tennesee, Texas, Utah and Virginia.

Kentucky has filed notice that it will appeal a federal ruling that it must recognize same-sex marriages from other states, making nine state whose cases are on appeal.

Utah's case is a week ahead of one in Oklahoma, which is scheduled for oral arguments in the 10th Circuit next Thursday. The same three judges will hear both cases.

Email: romboy@deseretnews.com, Twitter: dennisromboy