Attorney Rodney Parker argued his client has a right not only to believe in a religious tenet of polygamy but also to practice his belief in a meaningful way.

"The ban on plural marriage affects so many fundamental rights," he said, contending that tens of thousands of Utahns are forced to hide their relationships for fear of prosecution.

Parker asked the high court to decriminalize polygamy, allowing its adherents to have a legal marriage with a first wife, then enter into religious unions with other women as a way to reach the highest degree of heaven.

He stressed Holm is not asking for legal polygamy, which would make marriage to each wife state-sanctioned. Under his request, married individuals could also live as a spouse to other partners without being considered part of a common-law marriage and, therefore, bigamists.

"This issue deserves to be dealt with head-on," Parker said.

The justices launched into a spirited discussion on the legal intricacies of the case and society's changing relationships. They aimed numerous questions at Assistant Attorney General Laura Dupaix, asking how the Utah bigamy law is applied, whether only religious practitioners are targeted and the difference between cohabitating and purporting to marry.

Chief Justice Christine Durham wondered if living together as husband and wife is sufficient to have a legal marriage, or if a religious, non-state-sanctioned ceremony has to have occurred before someone can be guilty of bigamy.

Associate Chief Justice Michael Wilkins asked about possible constitutional conflicts between religious tolerance and a prohibition on polygamy. Justice Jill Parrish wondered if a man living with a fiancee while waiting for his divorce to be finalized is a bigamist.

Other comments centered on a 2003 U.S. Supreme Court decision that struck down a Texas anti-sodomy law as a violation of the privacy rights of consenting adults.

Dupaix defended the constitutionality of the Utah bigamy statute, which was used to prosecute Holm for his polygamous marriage with three women. She denied the law tramples on freedom of religion or association.

"No one is telling Mr. Holm that he can't belong to a church that believes in polygamy," Dupaix said.

The case is not just about private sexual conduct, she also said, but about "the public institution of marriage." Divorces would become complicated with more than two people entangled in custody and other issues, she said.

But Durham said judges have been dealing for years with sticky domestic situations, including ones involving live-in partners, same-sex couples and surrogate parents.

"There is nothing to suggest polygamous relationships would be more or less complicated," the chief justice said.

Holm is appealing bigamy and sex offense convictions that stem from his 1988 "spiritual" marriage to 16-year-old Ruth Stubbs, with whom he had two children. At the time, Holm was legally married to Stubbs' sister and had another spiritual wife.

The four were members of the Fundamentalist Church of Jesus Christ of Latter Day Saints, which embraces polygamy. Parker says Stubbs had her father's permission to marry and her union with Holm would have been legal if he had not been married to another woman.

Holm was sentenced in 2003 to one year in jail after his conviction in a jury trial and has since been released. He is registered as a sex offender and cannot return to his job in law enforcement. Stubbs no longer lives with him.

On Thursday, Parker contended Holm's plural marriage is different from that of a bigamist who commits fraud by making a wife believe he is single. In a polygamous situation, "all the cards are on the table and everyone knows," he said.

Utah Attorney General Mark Shurtleff, who attended Thursday's court session, acknowledged after the arguments that the state does not prosecute married people who live separately from their spouses with other partners. He said his office concentrates instead on cases involving underage girls or other offenses.

"We're just targeting criminals, child abusers," he said.

Holm, who also was in court, had no comment.

On Tuesday, the high court upheld the 2002 child-rape conviction of polygamist Tom Green for having sex with a 13-year-old who was his stepdaughter and one of his wives. He is serving a prison term of five years to life.

pmanson@sltrib.com