He said he would rule on the state's motion to dismiss "as soon as possible," but did not set a date for a decision.
Assistant Utah Attorney General Jerrold Jensen argued the Browns' lawsuit is moot because local prosecutors have pledged not to prosecute consenting adult polygamists, a policy similar to the state's that they adopted after the family sued.
"Utah County does not want to prosecute," Jensen said, saying no one can remember the last bigamy case there. "They could have brought charges [against the Browns] for a year and they didn't do it."
Under Waddoups' sharp questioning, Jensen called the law banning polygamy "moribund," but he did not articulate an ideological reason why prosecutors don't go after consenting adults. He instead reiterated Utah Attorney General Mark Shurtleff's long-stated position that it's not practical to charge the state's estimated 30,000 polygamists.
But Jonathan Turley, the Brown family's Washington, D.C.-based attorney, said that policy doesn't go far enough. He argues the law is an unconstitutional violation of privacy and should be taken off the books.
"A policy change is not a repeal ... they're not claiming the law is unenforceable," Turley said, adding that it's unclear how the policy was adopted and whether it's ever been announced to the public. "He could change that policy tomorrow."
He said the Browns are "hopeful" about the outcome of the case.
The polygamists Kody Brown and his four wives, Meri, Janelle, Christine and Robyn moved to Nevada when police opened an investigation after "Sister Wives" premiered in 2010, and did not appear at Wednesday's hearing. Neither did Utah County Attorney Jeff Buhman, relying instead on Jensen to present his side of the case.
Kody Brown on Wednesday released a statement saying that despite their "close ties," to Utah, they plan to remain in Nevada for the foreseeable future.
"We feel strongly that this law is unconstitutional and that the people of Utah should have a final decision on that question," he said.
Waddoups has already sided with the Browns once, allowing the case to proceed even though prosecutors never filed formal charges. He decided that prosecutors' media statements about a possible prosecution constituted a possible "chilling effect" on the family's freedom of speech.
Utah's bigamy law makes it a felony to marry or live with more than one spouse.