Attorney Peggy A. Tomsic, representing the plaintiffs, will share with the judges the "human reality" at the heart of the case and explain how the ban on gay marriage has "cemented" discrimination against same-sex couples, particularly those rearing children a prohibition that cannot stand under the U.S. Constitution's equal-protection and due-process clauses.
Some legal observers describe the randomly selected panel that will hear Utah's appeal as "slightly conservative." They are Judge Paul Kelly Jr. and Judge Jerome Holmes, both nominated by Republican presidents, and Judge Carlos Lucero, nominated by a Democrat.
Holmes was one of two judges who denied a series of requests from Utah for a stay of U.S. District Court Judge Robert J. Shelby's Dec. 20 ruling that the state's ban on same-sex marriage is unconstitutional.
The hearing to either uphold or strike down Shelby's ruling will be the second of three possible rounds in Utah's battle over marriage equality, and it is being closely watched as a precedent for what might happen elsewhere.
"For months now, the action on same-sex marriage has been in the federal district courts," said Stephen Wermiel, an American University Washington College of Law professor. "With the argument in the 10th Circuit this week on the Utah law, and next week on the Oklahoma law, the same-sex marriage issue moves one step closer to the U.S. Supreme Court, where it seems inevitable that the justices will eventually have to decide whether couples of the same sex have a right to marry."
The first round in Utah went to the three same-sex couples Derek Kitchen and Moudi Sbeity; Kate Call and Karen Archer; and Lauri Wood and Kody Partridge who challenged Utah's Amendment 3. Some 1,200 couples married before Shelby's decision was stayed 17 days later by the U.S. Supreme Court.
Tomsic and James E. Magleby, who are being joined in the appeal by attorneys from the National Center for Lesbian Rights, are confident they'll prevail again in Denver.
"When you look at the law ... there is no legal justification for the other side," Magleby said in a recent interview with The Salt Lake Tribune.
But Utah's attorneys say Shelby is an activist judge who misinterpreted and misapplied the law.
"The legal question at issue is not the fundamental right of same-sex couples to enter into exclusive and permanent relationships, raise children, or bequeath property at their death," said Utah Attorney General Sean Reyes in a February statement. "Utah law already gives those rights. The constitutional question is whether it is reasonable for Utah's citizens to believe that a child benefits most from being raised by his or her biological mother and father in a permanent relationship, and that such relationships should therefore be encouraged through recognition as marriages."
In its briefs, the state argues vehemently that social science research shows parenting by same-sex couples is inferior to that of opposite-sex couples. But findings of a primary researcher relied on by the state were flayed last month in a ruling for marriage equality by a federal judge in Michigan, who said Mark Regnerus' testimony was "entirely unbelievable and not worthy of serious consideration."
In a letter filed with the 10th Circuit on Friday, Schaerr said that decision, as well as one in Tennessee, are wrong and their findings irrelevant to the Utah case, but pointed out that the Michigan judge did not dispute that the debate over parenting quality has not been proved with scientific certainty.
"That failure of proof," Schaerr wrote, "buttresses Utah's conclusion that there exists at least a risk that, over the long run, children raised by same-sex couples will do worse than children raised by man-woman couples."
Reyes, who will travel to Denver with the three attorneys hired by the state to defend Utah's law, declined interview requests before Thursday's hearing.
What the state has emphasized in its voluminous filings with the court is that Shelby's decision, which held that gay couples have a fundamental right to marry, is a "judicial wrecking ball" that takes away the right of lawmakers and citizens to decide for themselves how marriage should be defined. Utah's attorneys also point to the fact that Amendment 3 was approved by 66 percent of voters who participated in the 2004 general election.
Marriage-equality proponents say that while states have a role to play in regulating marriage, that role is confined by constitutional protections as demonstrated in Loving v. Virginia, the U.S. Supreme Court's 1967 decision ending bans on interracial marriage that were approved by lawmakers and voters.
And more current assessments of public opinion, including one by The Tribune, show a significant shift in support for marriage equality during the past decade.
The Tribune's statewide poll, conducted in January, shows residents are evenly split 48-48 on whether same-sex couples in Utah should be allowed to get state-issued marriage licenses, and 72 percent support access to civil unions or domestic partnerships.
Most national polls show a majority of Americans now support same-sex marriage among them a February 2014 survey by Pew Research Center's Religion and Public Life Project, which said public support for gay marriage is currently at 54 percent, with 39 percent opposed.
A recent Washington Post/ABC News poll put support at 59 percent.
In a Tuesday conference call hosted by Freedom to Marry about Thursday's hearing, Mark McKinnon, an adviser to former President George W. Bush, said the swing in support, even among members of the GOP, resembles a "hockey stick" rather than a gradual curve.
Public sentiment aside, gay marriage remains off-limits in 33 states, and in 29 of those states there are constitutional bans similar to Utah's Amendment 3.
After decades of debate, however, legal challenges with Utah's at the forefront are underway across the nation that could finally settle the issue. There are approximately 60 cases pending in state and federal courts in 29 states and Puerto Rico.
Nine federal judges, including Shelby, have issued decisions in favor of the right of same-sex couples' access to civil marriage, finding state bans have no rational purpose; those decisions are now before five appellate courts.
The U.S. Supreme Court could opt to let the issue simmer, leaving in place whatever determinations the circuit courts make, as it did earlier this week in opting not to take an appeal brought by a New Mexico photographer. The photographer claimed First Amendment protection after being charged under an anti-discrimination law for refusing to shoot wedding photos for a lesbian couple.
The court also doesn't have to take the first case it receives. It could opt for a representative case and some observers say a possible candidate might be a case from the 6th Circuit Court of Appeals, where lawsuits are pending from every state in its purview: Michigan, Kentucky, Tennessee and Ohio.
"All I really care about at the end of the day," Tomsic said in an interview, "is whoever is the one that gets to argue before the Supreme Court and it may not even be any of our cases, it may be a case after this I just want them to win."
Wermiel said it is difficult to predict what the Supreme Court's timing will be.
"The justices may want to wait until more than one federal appeals court has considered the same-sex marriage issue or until there is some difference of opinion among different federal circuits. Waiting would give the justices the benefit of the thinking of more judges, something they usually prize."
Carl Tobias, a law professor at the University of Richmond, said that by summer's end there should be a number of appellate decisions, the 10th Circuit's among them, for the high court to weigh.
"The justices will want to see whether the courts agree and the reasoning used," said Tobias, agreeing that the court will be more likely to take a case if there are split decisions. "It may set the tone for the other [circuit courts] and give them reasons for deciding a particular way."
And that is why all eyes are now on Utah's case at the 10th Circuit Court in Denver.
A case in motion
March 25, 2013: Complaint filed in U.S. District Court for Utah on behalf of Derek Kitchen and Moudi Sbeity; Kate Call and Karen Archer; Laurie Wood and Kody Partridge.
Dec. 4, 2013: Oral arguments in Kitchen v. Herbert before U.S. District Court Judge Robert J. Shelby.
Dec. 20, 2013: Shelby grants summary judgment to plaintiffs, finding Utah's Amendment 3 and other laws banning same-sex marriage unconstitutional.
Dec. 20, 2013: State files first of three appeals with 10th U.S. Circuit Court of Appeals in Denver; also requests hearing before Shelby on stay.
Dec. 23, 2013: After hearing arguments, Shelby denies state's request for a stay. The 10th Circuit, in two rulings, also denies stay request.
Dec. 24, 2013: The 10th Circuit denies stay but agrees to hear appeal.
Dec. 31, 2013: State files stay application with U.S. Supreme Court. It is assigned to Justice Sonia Sotomayor, who oversees the 10th Circuit.
Jan. 6, 2014: At 8:32 a.m. MST, the U.S. Supreme Court stays Shelby's ruling while Utah appeals it.
Jan. 8, 2014: Utah Attorney General Sean Reyes announces it will "freeze" the approximately 1,200 marriages that took place between ruling and stay decision and not recognize them.
April 10, 2014: The 10th Circuit hears arguments in Kitchen v. Herbert.
A look at marriage laws in 10th Circuit states
There are six states, including Utah, within the jurisdiction of the 10th U.S. Circuit Court of Appeals. Here's the status of marriage equality in the circuit's five other states:
Colorado: In 2013, the state approved civil unions. A constitutional amendment bars marriages of same-sex couples.
Kansas: A constitutional amendment adopted in 2005 prohibits same-sex marriage and recognition of marriages performed in other states. In February, the state Legislature adopted a law protecting the right of religious individuals, groups and businesses to refuse service to same-sex couples.
New Mexico: In December 2013, the New Mexico Supreme Court ruled that nothing in state law bars same-sex marriage.
Oklahoma: In 2004, voters approved a constitutional amendment banning same-sex marriage and recognition of marriages performed in other states. On Jan. 14, a federal judge ruled the state's ban is unconstitutional. The 10th Circuit will hear an appeal April 17.
Wyoming: In 1977, the state Legislature approved a statute that bars same-sex marriage or recognition of marriages performed in other states. A movement to add that ban to the state's constitutional has failed so far.